Start and end datesIt is generally considered that in World War II started on 1 September 1939, beginning with the and the United Kingdom and France's declaration of war on Germany two days later. The dates for the beginning of the war in the Pacific include the start of the on 7 July 1937, or the earlier , on 19 September 1931. Others follow the British historian , who held that the Sino-Japanese War and war in Europe and its colonies occurred simultaneously, and the two wars became World War II in 1941. Other starting dates sometimes used for World War II include the on 3 October 1935. The British historian views the beginning of World WarII as the fought between and the forces of and the from May to September 1939. Others view the as the start or prelude to World War II. The exact date of the war's end is also not universally agreed upon. It was generally accepted at the time that the war ended with the of 14 August 1945 ( ), rather than with the formal on 2 September 1945, which officially ended the war in Asia. A peace treaty between Japan and the Allies was signed in 1951. A 1990 treaty regarding Germany's future allowed the reunification of East and West Germany to take place and resolved most post-World WarII issues. No formal peace treaty between Japan and the Soviet Union was ever signed, although the state of war between the two countries was terminated by the , which also restored full diplomatic relations between them.''Texts of Soviet–Japanese Statements; Peace Declaration Trade Protocol.''
Europehad radically altered the European map, with the defeat of the —including , , and the —and the 1917 in , which led to the founding of the . Meanwhile, the victorious , such as France, , Italy, , and , gained territory, and new were created out of the and the and s. To prevent a future world war, the was created during the . The organisation's primary goals were to prevent armed conflict through , military and , and settling international disputes through peaceful negotiations and arbitration. Despite strong sentiment after World WarI, and emerged in several European states in the same period. These sentiments were especially marked in Germany because of the significant territorial, colonial, and financial losses imposed by the . Under the treaty, Germany lost around 13 percent of its home territory and all its overseas possessions, while German annexation of other states was prohibited, were imposed, and limits were placed on the size and capability of the country's . The German Empire was dissolved in the , and a democratic government, later known as the , was created. The interwar period saw strife between supporters of the new republic and hardline opponents on both the and . Italy, as an Entente ally, had made some post-war territorial gains; however, Italian nationalists were angered that the promises made by the United Kingdom and France to secure Italian entrance into the war were not fulfilled in the peace settlement. From 1922 to 1925, the movement led by seized power in Italy with a nationalist, , and ist agenda that abolished representative democracy, repressed socialist, left-wing and liberal forces, and pursued an aggressive expansionist foreign policy aimed at making Italy a world power, and promising the creation of a " New Roman Empire". , after an Beer Hall Putsch, unsuccessful attempt to overthrow the German government in 1923, eventually Adolf Hitler's rise to power, became the Chancellor of Germany in 1933 when Paul Von Hindenburg and the Reichstag appointed him. He abolished democracy, espousing a New Order (Nazism), radical, racially motivated revision of the world order, and soon began a massive German re-armament, rearmament campaign. Meanwhile, France, to secure its alliance, Franco-Italian Agreement, allowed Italy a free hand in Ethiopia, which Italy desired as a colonial possession. The situation was aggravated in early 1935 when the Saar (League of Nations), Territory of the Saar Basin was legally reunited with Germany, and Hitler repudiated the Treaty of Versailles, accelerated his rearmament programme, and introduced conscription. The United Kingdom, France and Italy formed the Stresa Front in April 1935 in order to contain Germany, a key step towards military globalisation; however, that June, the United Kingdom made an Anglo-German Naval Agreement, independent naval agreement with Germany, easing prior restrictions. The Soviet Union, concerned by Drang nach Osten, Germany's goals of capturing vast areas of Eastern Europe, drafted a treaty of mutual assistance with France. Before taking effect, though, the Franco-Soviet pact was required to go through the bureaucracy of the League of Nations, which rendered it essentially toothless. The United States, concerned with events in Europe and Asia, passed the Neutrality Acts of 1930s, Neutrality Act in August of the same year. Hitler defied the Versailles and Locarno treaties by Remilitarization of the Rhineland, remilitarising the Rhineland in March 1936, encountering little opposition due to the policy of appeasement. In October 1936, Germany and Italy formed the Rome–Berlin Axis. A month later, Germany and Japan signed the Anti-Comintern Pact, which Italy joined the following year.
AsiaThe Kuomintang (KMT) party in China launched a Northern Expedition, unification campaign against Warlord Era, regional warlords and nominally unified China in the mid-1920s, but was soon embroiled in Chinese Civil War, a civil war against its former Chinese Communist Party allies and Central Plains War, new regional warlords. In 1931, an Statism in Shōwa Japan, increasingly militaristic Empire of Japan, which had long sought influence in China as the first step of what its government saw as the country's Hakko ichiu, right to rule Asia, staged the Mukden Incident as a pretext to Japanese invasion of Manchuria, invade Manchuria and establish the puppet state of Manchukuo. China appealed to the to stop the Japanese invasion of Manchuria. Japan withdrew from the League of Nations after being Lytton Report, condemned for its incursion into Manchuria. The two nations then fought several battles, in 28 January Incident, Shanghai, Battle of Rehe, Rehe and Defense of the Great Wall, Hebei, until the Tanggu Truce was signed in 1933. Thereafter, Chinese volunteer forces continued the resistance to Japanese aggression in Pacification of Manchukuo, Manchuria, and Actions in Inner Mongolia (1933–1936), Chahar and Suiyuan. After the 1936 Xi'an Incident, the Kuomintang and communist forces agreed on a ceasefire to present Second United Front, a united front to oppose Japan.
Italian invasion of Ethiopia (1935)The Second Italo-Ethiopian War was a brief colonial war that began in October 1935 and ended in May 1936. The war began with the invasion of the Ethiopian Empire (also known as Ethiopia#Etymology, Abyssinia) by the armed forces of the Kingdom of Italy (''Regno d'Italia''), which was launched from Italian Somaliland and Italian Eritrea, Eritrea. The war resulted in the military occupation of Ethiopia and its annexation into the newly created colony of Italian East Africa (''Africa Orientale Italiana'', or AOI); in addition it exposed the weakness of the as a force to preserve peace. Both Italy and Ethiopia were member nations, Appeasement, but the League did little when the former clearly violated Article X of the League's Covenant of the League of Nations, Covenant. The United Kingdom and France supported imposing sanctions on Italy for the invasion, but the sanctions were not fully enforced and failed to end the Italian invasion. Italy subsequently dropped its objections to Germany's goal of absorbing Federal State of Austria, Austria.
Spanish Civil War (1936–1939)When civil war broke out in Spain, Hitler and Mussolini lent military support to the Nationalist faction (Spanish Civil War), Nationalist rebels, led by General Francisco Franco. Italy supported the Nationalists to a greater extent than the Nazis did: altogether Mussolini sent to Spain more than 70,000 ground troops and 6,000 aviation personnel, as well as about 720 aircraft. The Soviet Union supported the existing government of the Second Spanish Republic, Spanish Republic. More than 30,000 foreign volunteers, known as the International Brigades, also fought against the Nationalists. Both Germany and the Soviet Union used this proxy war as an opportunity to test in combat their most advanced weapons and tactics. The Nationalists won the civil war in April 1939; Franco, now dictator, remained officially neutral during World WarII but Spain during World War II, generally favoured the Axis. His greatest collaboration with Germany was the sending of Blue Division, volunteers to fight on the Eastern Front (World War II), Eastern Front.
Japanese invasion of China (1937)In July 1937, Japan captured the former Chinese imperial capital of Beijing, Peking after instigating the Marco Polo Bridge Incident, which culminated in the Japanese campaign to invade all of China. The Soviets quickly signed a Sino-Soviet Non-Aggression Pact, non-aggression pact with China to lend materiel support, effectively ending China's prior Sino-German cooperation (1926–1941), co-operation with Germany. From September to November, the Japanese attacked Battle of Taiyuan, Taiyuan, engaged the National Revolutionary Army, Kuomintang Army Battle of Xinkou, around Xinkou,. and fought Chinese Communist Party, Communist forces Battle of Pingxingguan, in Pingxingguan.Yang Kuisong, "On the reconstruction of the facts of the Battle of Pingxingguan" Generalissimo Chiang Kai-shek deployed his List of German-trained divisions of the National Revolutionary Army, best army to Battle of Shanghai, defend Shanghai, but after three months of fighting, Shanghai fell. The Japanese continued to push the Chinese forces back, Battle of Nanking, capturing the capital Nanking in December 1937. After the fall of Nanking, tens or hundreds of thousands of Chinese civilians and disarmed combatants were Nanjing Massacre, murdered by the Japanese.Totten, Samuel. ''Dictionary of Genocide''. 2008, 298–99. In March 1938, Nationalist Chinese forces won their Battle of Taierzhuang, first major victory at Taierzhuang, but then the city of Xuzhou Battle of Xuzhou, was taken by the Japanese in May. In June 1938, Chinese forces stalled the Japanese advance by 1938 Yellow River flood, flooding the Yellow River; this manoeuvre bought time for the Chinese to prepare their defences at Wuhan, but the Battle of Wuhan, city was taken by October. Japanese military victories did not bring about the collapse of Chinese resistance that Japan had hoped to achieve; instead, the Chinese government relocated inland to Chongqing and continued the war.
Soviet–Japanese border conflictsIn the mid-to-late 1930s, Japanese forces in Manchukuo had sporadic border clashes with the Soviet Union and Mongolian People's Republic, Mongolia. The Japanese doctrine of Hokushin-ron, which emphasised Japan's expansion northward, was favoured by the Imperial Army during this time. With the Japanese defeat at Battles of Khalkhin Gol, Khalkin Gol in 1939, the ongoing Second Sino-Japanese War and ally Nazi Germany pursuing neutrality with the Soviets, this policy would prove difficult to maintain. Japan and the Soviet Union eventually signed a Soviet–Japanese Neutrality Pact, Neutrality Pact in April 1941, and Japan adopted the doctrine of Nanshin-ron, promoted by the Navy, which took its focus southward, eventually leading to its war with the United States and the Western Allies.
European occupations and agreementsIn Europe, Germany and Italy were becoming more aggressive. In March 1938, Germany Anschluss, annexed Austria, again provoking appeasement, little response from other European powers. Encouraged, Hitler began pressing German claims on the Sudetenland, an area of Czechoslovakia with a predominantly Germans, ethnic German population. Soon the United Kingdom and France followed the appeasement policy of British Prime Minister Neville Chamberlain and conceded this territory to Germany in the Munich Agreement, which was made against the wishes of the Czechoslovak government, in exchange for a promise of no further territorial demands. Soon afterwards, Germany and Italy forced Czechoslovakia to First Vienna Award, cede additional territory to Hungary, and Poland annexed Czechoslovakia's Zaolzie region. Although all of Germany's stated demands had been satisfied by the agreement, privately Hitler was furious that British interference had prevented him from seizing all of Czechoslovakia in one operation. In subsequent speeches Hitler attacked British and Jewish "war-mongers" and in January 1939 Plan Z, secretly ordered a major build-up of the German navy to challenge British naval supremacy. In March 1939, German occupation of Czechoslovakia, Germany invaded the remainder of Czechoslovakia and subsequently split it into the German Protectorate of Bohemia and Moravia and a pro-German client state, the Slovak Republic (1939–1945), Slovak Republic. Hitler also delivered an 1939 German ultimatum to Lithuania, ultimatum to Lithuania on 20 March 1939, forcing the concession of the Klaipėda Region, formerly the German ''Memelland''. Greatly alarmed and with Hitler making further demands on the Free City of Danzig, the United Kingdom and France Anglo-Polish military alliance#British Guarantee to Poland, guaranteed their support for Polish independence; when Italian invasion of Albania, Italy conquered Albania in April 1939, the same guarantee was extended to the Kingdom of Romania, Kingdoms of Romania and Kingdom of Greece, Greece. Shortly after the Franco-Polish alliance (1921), Franco-Anglo-Polish military alliance, British pledge to Poland, Germany and Italy formalised their own alliance with the Pact of Steel. Hitler accused the United Kingdom and Poland of trying to "encircle" Germany and renounced the Anglo-German Naval Agreement and the German–Polish Non-Aggression Pact. The situation reached a general crisis in late August as German troops continued to mobilise against the Polish border. On 23 August, when tripartite negotiations about a military alliance between France, the United Kingdom and Soviet Union stalled, the Soviet Union signed Molotov–Ribbentrop Pact, a non-aggression pact with Germany. This pact had a secret protocol that defined German and Soviet "spheres of influence" (western Second Polish Republic, Poland and Lithuania for Germany; Territories of Poland annexed by the Soviet Union, eastern Poland, Finland, Estonia, Latvia and Bessarabia for the Soviet Union), and raised the question of continuing Polish independence. The pact neutralised the possibility of Soviet opposition to a campaign against Poland and assured that Germany would not have to face the prospect of a two-front war, as it had in World WarI. Immediately after that, Hitler ordered the attack to proceed on 26 August, but upon hearing that the United Kingdom had concluded a formal mutual assistance pact with Poland and that Italy would maintain neutrality, he decided to delay it. In response to British requests for direct negotiations to avoid war, Germany made demands on Poland, which only served as a pretext to worsen relations. On 29 August, Hitler demanded that a Polish plenipotentiary immediately travel to Berlin to negotiate the handover of Gdańsk, Danzig, and to allow a referendum, plebiscite in the Polish Corridor in which the German minority would vote on secession. The Poles refused to comply with the German demands, and on the night of 30–31 August in a stormy meeting with the British ambassador Nevile Henderson, Ribbentrop declared that Germany considered its claims rejected.
Course of the war
War breaks out in Europe (1939–40)On 1 September 1939, Germany Invasion of Poland, invaded Poland after Operation Himmler, having staged several Gleiwitz incident, false flag border incidents as a pretext to initiate the invasion. The first German attack of the war came against the Battle of Westerplatte, Polish defenses at Westerplatte. The United Kingdom responded with an ultimatum to Germany to cease military operations, and on 3 September, after the ultimatum was ignored, Britain and France declared war on Germany, followed by Australia, Dominion of New Zealand, New Zealand, Union of South Africa, South Africa and Canada. The alliance provided Phoney War, no direct military support to Poland, outside of a Saar Offensive, cautious French probe into the Saarland..
Western Europe (1940–41)In April 1940, Operation Weserübung, Germany invaded Denmark and Norway to protect shipments of Swedish iron-ore mining during World War II, iron ore from Sweden, which the Allies were Operation Wilfred, attempting to cut off. Denmark capitulated after a few hours, and Norway was conquered within two months Norwegian campaign, despite Allied support. Norway Debate, British discontent over the Norwegian campaign led to the appointment of Winston Churchill as Prime Minister on 10May 1940. On the same day, Germany Battle of France, launched an offensive against France. To circumvent the strong Maginot Line fortifications on the Franco-German border, Germany directed its attack at the neutral nations of Battle of Belgium, Belgium, Battle of the Netherlands, the Netherlands, and German invasion of Luxembourg, Luxembourg. The Germans carried out a flanking manoeuvre through the Ardennes region, which was mistakenly perceived by Allies as an impenetrable natural barrier against armoured vehicles. By successfully implementing new blitzkrieg tactics, the ''Wehrmacht'' rapidly advanced to the Channel and cut off the Allied forces in Belgium, trapping the bulk of the Allied armies in a cauldron on the Franco-Belgian border near Lille. The United Kingdom was able Dunkirk evacuation, to evacuate a significant number of Allied troops from the continent by early June, although abandoning almost all their equipment. On 10 June, Italian invasion of France, Italy invaded France, declaring war on both France and the United Kingdom. The Germans turned south against the weakened French army, and Paris in World War II, Paris fell to them on 14June. Eight days later Armistice of 22 June 1940, France signed an armistice with Germany; it was divided into German military administration in occupied France during World War II, German and Italian occupation of France, Italian occupation zones, and an unoccupied rump state under the Vichy France, Vichy Regime, which, though officially neutral, was generally aligned with Germany. France kept its fleet, which Attack on Mers-el-Kébir, the United Kingdom attacked on 3July in an attempt to prevent its seizure by Germany. The air began in early July with Kanalkampf, Luftwaffe attacks on shipping and harbours. The United Kingdom rejected Hitler's peace offer, and the Adlertag, German air superiority campaign started in August but failed to defeat RAF Fighter Command, forcing the indefinite postponement of the Operation Sea Lion, proposed German invasion of Britain. The German offensive intensified with night attacks on London and other cities in , but failed to significantly disrupt the British war effort and largely ended in May 1941. Using newly captured French ports, the German Navy Battle of the Atlantic#'The Happy Time' (June 1940 – February 1941), enjoyed success against an over-extended Royal Navy, using U-boats against British shipping Battle of the Atlantic, in the Atlantic. The British Home Fleet scored a significant victory on 27May 1941 by Last battle of the battleship Bismarck, sinking the German battleship ''Bismarck''. In November 1939, the United States was taking measures to assist China and the Western Allies and amended the Neutrality Acts of the 1930s, Neutrality Act to allow Cash and carry (World War II), "cash and carry" purchases by the Allies. In 1940, following the German capture of Paris, the size of the United States Navy was Two-Ocean Navy Act, significantly increased. In September the United States further agreed to a Destroyers-for-bases deal, trade of American destroyers for British bases. Still, a large majority of the American public continued to oppose any direct military intervention in the conflict well into 1941. In December 1940 Roosevelt accused Hitler of planning world conquest and ruled out any negotiations as useless, calling for the United States to become an "Arsenal of Democracy, arsenal of democracy" and promoting Lend-Lease programmes of aid to support the British war effort. The United States started strategic planning to prepare for a full-scale offensive against Germany. At the end of September 1940, the Tripartite Pact formally united Japan, Italy, and Germany as the Axis powers. The Tripartite Pact stipulated that any country, with the exception of the Soviet Union, which attacked any Axis Power would be forced to go to war against all three. The Axis expanded in November 1940 when Hungary, Slovakia and Kingdom of Romania, Romania joined. Romania in World War II, Romania and Hungary in World War II, Hungary later made major contributions to the Axis war against the Soviet Union, in Romania's case partially to recapture Soviet occupation of Bessarabia and northern Bukovina, territory ceded to the Soviet Union.
Mediterranean (1940–41)In early June 1940, the Italian ''Regia Aeronautica'' Siege of Malta (World War II), attacked and besieged Malta, a British possession. From late summer to early autumn, Italy Italian invasion of British Somaliland, conquered British Somaliland and made an Italian invasion of Egypt, incursion into British-held Egypt. In October, Greco-Italian War, Italy attacked Greece, but the attack was repulsed with heavy Italian casualties; the campaign ended within months with minor territorial changes. Germany started preparation for an invasion of the Balkans to assist Italy, to prevent the British from gaining a foothold there, which would be a potential threat for Romanian oil fields, and to strike against the British dominance of the Mediterranean. In December 1940, British Empire forces began Operation Compass, counter-offensives against Italian forces in Egypt and East African campaign (World War II), Italian East Africa. The offensives were highly successful; by early February 1941, Italy had lost control of eastern Libya, and large numbers of Italian troops had been taken prisoner. The Regia Marina, Italian Navy also suffered significant defeats, with the Royal Navy putting three Italian battleships out of commission by means of a Battle of Taranto, carrier attack at Taranto, and neutralising several more warships at the Battle of Cape Matapan. Italian defeats prompted Germany to Operation Sonnenblume, deploy an expeditionary force to North Africa and at the end of March 1941, Erwin Rommel, Rommel's Afrika Korps Western Desert campaign, launched an offensive which drove back the Commonwealth forces. In under a month, Axis forces advanced to western Egypt and Siege of Tobruk, besieged the port of Tobruk. By late March 1941, Bulgaria and Yugoslavia signed the Tripartite Pact; however, the Yugoslav government was Yugoslav coup d'état, overthrown two days later by pro-British nationalists. Germany responded with simultaneous invasions of both Invasion of Yugoslavia, Yugoslavia and Battle of Greece, Greece, commencing on 6 April 1941; both nations were forced to surrender within the month. The airborne Battle of Crete, invasion of the Greek island of Crete at the end of May completed the German conquest of the Balkans. Although the Axis victory was swift, bitter and large-scale partisan warfare subsequently broke out against the World War II in Yugoslavia, Axis occupation of Yugoslavia, which continued until the end of the war. In the Middle East in May, Commonwealth forces Anglo-Iraqi War, quashed an uprising in Iraq which had been supported by German aircraft from bases within Vichy-controlled Mandate for Syria and the Lebanon, Syria. Between June and July, they Syria–Lebanon campaign, invaded and occupied the French possessions Syria and Lebanon, with the assistance of the Free France, Free French.
Axis attack on the Soviet Union (1941)With the situation in Europe and Asia relatively stable, Germany, Japan, and the Soviet Union made preparations. With the Soviets wary of mounting tensions with Germany and the Japanese planning to take advantage of the European War by seizing resource-rich European possessions in Southeast Asia, the two powers signed the Soviet–Japanese Neutrality Pact in April 1941. By contrast, the Germans were steadily making preparations for an attack on the Soviet Union, massing forces on the Soviet border. Hitler believed that the United Kingdom's refusal to end the war was based on the hope that the United States and the Soviet Union would enter the war against Germany sooner or later. On 31 July 1940 Hitler decided that the Soviet Union should be eliminated and aimed for the conquest of Ukraine, the Baltic states and Belorussia.. However, other senior German officials like Ribbentrop saw an opportunity to create a Euro-Asian bloc against the British Empire by inviting the Soviet Union into the Tripartite Pact.. In November 1940, German–Soviet Axis talks, negotiations took place to determine if the Soviet Union would join the pact. The Soviets showed some interest but asked for concessions from Finland, Bulgaria, Turkey, and Japan that Germany considered unacceptable. On 18 December 1940, Hitler issued the directive to prepare for an invasion of the Soviet Union. On 22 June 1941, Germany, supported by Italy and Romania, invaded the Soviet Union in Operation Barbarossa, with Germany accusing the Soviets of plotting against them. They were joined shortly by Finland and Hungary.. The primary targets of this surprise offensive were the Baltic region, Moscow and Ukraine, with the Strategic goal (military), ultimate goal of ending the 1941 campaign near the A-A line, Arkhangelsk-Astrakhan line, from the Caspian Sea, Caspian to the White Seas. Hitler's objectives were to eliminate the Soviet Union as a military power, exterminate Communism, generate ''Lebensraum'' ("living space") by Generalplan Ost, dispossessing the native population and guarantee access to the strategic resources needed to defeat Germany's remaining rivals. Although the Red Army was preparing for strategic counter-offensives before the war, ''Operation'' ''Barbarossa'' forced the Stavka, Soviet supreme command to adopt a strategic defence. During the summer, the Axis made significant gains into Soviet territory, inflicting immense losses in both personnel and materiel. By mid-August, however, the German Oberkommando des Heeres, Army High Command decided to Battle of Smolensk (1941), suspend the offensive of a considerably depleted Army Group Centre, and to divert the 2nd Panzer Army, 2nd Panzer Group to reinforce troops advancing towards central Ukraine and Leningrad. The Battle of Kiev (1941), Kiev offensive was overwhelmingly successful, resulting in encirclement and elimination of four Soviet armies, and made possible further Crimean campaign, advance into Crimea and industrially developed Eastern Ukraine (the First Battle of Kharkov). The diversion of three quarters of the Axis troops and the majority of their air forces from France and the central Mediterranean to the Eastern Front (World War II), Eastern Front prompted the United Kingdom to reconsider its grand strategy. In July, the UK and the Soviet Union formed a Anglo-Soviet Agreement, military alliance against Germany and in August, the United Kingdom and the United States jointly issued the Atlantic Charter, which outlined British and American goals for the postwar world. In late August the British and Soviets Anglo-Soviet invasion of Iran, invaded neutral Iran to secure the Persian Corridor, Iran's Petroleum reservoir#Oil field, oil fields, and preempt any Axis advances through Iran toward the Baku oil fields or British India. By October Axis operational objectives in Ukraine and the Baltic region were achieved, with only the sieges of siege of Leningrad, Leningrad and Siege of Sevastopol (1941–1942), Sevastopol continuing. A major Battle of Moscow, offensive against Moscow was renewed; after two months of fierce battles in increasingly harsh weather, the German army almost reached the outer suburbs of Moscow, where the exhausted troops were forced to suspend their offensive. Large territorial gains were made by Axis forces, but their campaign had failed to achieve its main objectives: two key cities remained in Soviet hands, the Soviet Military capability, capability to resist was not broken, and the Soviet Union retained a considerable part of its military potential. The ''blitzkrieg'' Phase (combat), phase of the war in Europe had ended. By early December, freshly mobilised Military reserve force, reserves allowed the Soviets to achieve numerical parity with Axis troops. This, as well as Richard Sorge#Wartime intelligence, intelligence data which established that a minimal number of Soviet troops in the East would be sufficient to deter any attack by the Japanese Kwantung Army, allowed the Soviets to begin a winter campaign of 1941–42, massive counter-offensive that started on 5 December all along the front and pushed German troops west.
War breaks out in the Pacific (1941)Following the Japanese false flag Mukden Incident in 1931, the Japanese shelling of the American USS Panay incident, gunboat ''USS Panay'' in 1937, and the 1937-38 Nanjing Massacre, Japan–United States relations#1937–1941, Japanese-American relations deteriorated. In 1939, the United States notified Japan that it would not be extending its trade treaty and American public opinion opposing Japanese expansionism led to a series of economic sanctions, the Export Control Acts, which banned U.S. exports of chemicals, minerals and military parts to Japan and increased economic pressure on the Japanese regime.Maechling, Charles. ''Pearl Harbor: The First Energy War''. History Today. December 2000 During 1939 Japan launched its Battle of Changsha (1939), first attack against Changsha, a strategically important Chinese city, but was repulsed by late September. Despite 1939–40 Winter Offensive, several offensives by both sides, the war between China and Japan was stalemated by 1940. To increase pressure on China by blocking supply routes, and to better position Japanese forces in the event of a war with the Western powers, Japan invaded and Japanese invasion of French Indochina, occupied northern Indochina in September 1940. Chinese nationalist forces launched a large-scale 1939–40 Winter Offensive, counter-offensive in early 1940. In August, Chinese Communist Party, Chinese communists launched an Hundred Regiments Offensive, offensive in Central China; in retaliation, Japan instituted Three Alls Policy, harsh measures in occupied areas to reduce human and material resources for the communists. The continued antipathy between Chinese communist and nationalist forces New Fourth Army incident, culminated in armed clashes in January 1941, effectively ending their co-operation. In March, the Japanese 11th army attacked the headquarters of the Chinese 19th army but was repulsed during Battle of Shanggao. In September, Japan attempted to Battle of Changsha (1941), take the city of Changsha again and clashed with Chinese nationalist forces. German successes in Europe encouraged Japan to increase pressure on European governments in Southeast Asia. The Dutch government agreed to provide Japan with some oil supplies from the Dutch East Indies, but negotiations for additional access to their resources ended in failure in June 1941. In July 1941 Japan sent troops to southern Indochina, thus threatening British and Dutch possessions in the Far East. The United States, the United Kingdom, and other Western governments reacted to this move with a freeze on Japanese assets and a total oil embargo. At the same time, Japan was Kantokuen, planning an invasion of the Soviet Far East, intending to capitalise off the German invasion in the west, but abandoned the operation after the sanctions. Since early 1941 the United States and Japan had been engaged in negotiations in an attempt to improve their strained relations and end the war in China. During these negotiations, Japan advanced a number of proposals which were dismissed by the Americans as inadequate. At the same time the United States, the United Kingdom, and the Netherlands engaged in secret discussions for the joint defence of their territories, in the event of a Japanese attack against any of them. Roosevelt reinforced Commonwealth of the Philippines, the Philippines (an American protectorate scheduled for independence in 1946) and warned Japan that the United States would react to Japanese attacks against any "neighboring countries". Frustrated at the lack of progress and feeling the pinch of the American–British–Dutch sanctions, Japan prepared for war. On 20 November, a new government under Hideki Tojo presented an interim proposal as its final offer. It called for the end of American aid to China and for lifting the embargo on the supply of oil and other resources to Japan. In exchange, Japan promised not to launch any attacks in Southeast Asia and to withdraw its forces from southern Indochina. The American counter-proposal of 26 November required that Japan evacuate all of China without conditions and conclude non-aggression pacts with all Pacific powers. That meant Japan was essentially forced to choose between abandoning its ambitions in China, or seizing the natural resources it needed in the Dutch East Indies by force; the Japanese military did not consider the former an option, and many officers considered the oil embargo an unspoken declaration of war. Japan planned to rapidly seize European colonies in Asia to create a large defensive perimeter stretching into the Central Pacific. The Japanese would then be free to exploit the resources of Southeast Asia while exhausting the over-stretched Allies by fighting a defensive war. To prevent American intervention while securing the perimeter, it was further planned to neutralise the United States Pacific Fleet and the American military presence in the Philippines from the outset. On 7 December 1941 (8 December in Asian time zones), Japan attacked British and American holdings with near-simultaneous Pacific War#Japanese offensives, 1941–42, offensives against Southeast Asia and the Central Pacific. These included an Attack on Pearl Harbor, attack on the American fleets at Pearl Harbor and Philippines campaign (1941–1942), the Philippines, Battle of Guam (1941), Guam, Battle of Wake Island, Wake Island, Malayan campaign, landings in Malaya, Japanese invasion of Thailand, Thailand and the Battle of Hong Kong. The Japanese invasion of Thailand led to Thailand's decision to ally itself with Japan and the other Japanese attacks led the United States declaration of war on Japan, United States, United Kingdom declaration of war on Japan, United Kingdom, China, Australia, and several other states to formally declare war on Japan, whereas the Soviet Union, being heavily involved in large-scale hostilities with European Axis countries, maintained its neutrality agreement with Japan. Germany, followed by the other Axis states, declared war on the United States in solidarity with Japan, citing as justification the American attacks on German war vessels that had been ordered by Roosevelt.
Axis advance stalls (1942–43)On 1 January 1942, the Four Policemen, Allied Big Four—the Soviet Union, China, the United Kingdom and the United States—and 22 smaller or exiled governments issued the Declaration by United Nations, thereby affirming the Atlantic Charter, and agreeing not to sign a separate peace with the Axis powers. During 1942, Allied officials debated on the appropriate grand strategy to pursue. All agreed that Europe first, defeating Germany was the primary objective. The Americans favoured a straightforward, Operation Sledgehammer, large-scale attack on Germany through France. The Soviets were also demanding a second front. The British, on the other hand, argued that military operations should target peripheral areas to wear out German strength, leading to increasing demoralisation, and bolster resistance forces. Germany itself would be subject to a heavy bombing campaign. An offensive against Germany would then be launched primarily by Allied armour without using large-scale armies. Eventually, the British persuaded the Americans that a landing in France was infeasible in 1942 and they should instead focus on driving the Axis out of North Africa. At the Casablanca Conference in early 1943, the Allies reiterated the statements issued in the 1942 Declaration and demanded the unconditional surrender of their enemies. The British and Americans agreed to continue to press the initiative in the Mediterranean by invading Sicily to fully secure the Mediterranean supply routes. Although the British argued for further operations in the Balkans to bring Turkey into the war, in May 1943, the Americans extracted a British commitment to limit Allied operations in the Mediterranean to an invasion of the Italian mainland and to invade France in 1944.
Pacific (1942–43)By the end of April 1942, Japan and its ally Thailand in World War II, Thailand had almost fully conquered Japanese invasion of Burma, Burma, Malayan campaign, Malaya, Dutch East Indies campaign, the Dutch East Indies, Battle of Singapore, Singapore, and Battle of Rabaul (1942), Rabaul, inflicting severe losses on Allied troops and taking a large number of prisoners. Despite stubborn Philippines campaign (1941–1942), resistance by Filipino and US forces, the Commonwealth of the Philippines, Philippine Commonwealth was eventually captured in May 1942, forcing its government into exile. On 16 April, in Burma, 7,000 British soldiers were encircled by the Japanese 33rd Division during the Battle of Yenangyaung and rescued by the Chinese 38th Division. Japanese forces also achieved naval victories in the Sinking of Prince of Wales and Repulse, South China Sea, Battle of the Java Sea, Java Sea and Indian Ocean raid, Indian Ocean, and Bombing of Darwin, bombed the Allied naval base at Darwin, Northern Territory, Darwin, Australia. In January 1942, the only Allied success against Japan was a Chinese Battle of Changsha (1941–42), victory at Changsha. These easy victories over the unprepared US and European opponents left Japan overconfident, as well as overextended. In early May 1942, Japan initiated operations to Operation Mo, capture Port Moresby by amphibious warfare, amphibious assault and thus sever communications and supply lines between the United States and Australia. The planned invasion was thwarted when an Allied task force, centred on two American fleet carriers, fought Japanese naval forces to a draw in the Battle of the Coral Sea. Japan's next plan, motivated by the earlier Doolittle Raid, was to seize Midway Atoll and lure American carriers into battle to be eliminated; as a diversion, Japan would also send forces to Aleutian Islands campaign, occupy the Aleutian Islands in Alaska. In mid-May, Japan started the Zhejiang-Jiangxi campaign in China, with the goal of inflicting retribution on the Chinese who aided the surviving American airmen in the Doolittle Raid by destroying Chinese air bases and fighting against the Chinese 23rd and 32nd Army Groups. In early June, Japan put its operations into action, but the Americans, having broken Japanese naval codes in late May, were fully aware of the plans and order of battle, and used this knowledge to achieve a decisive Battle of Midway, victory at Midway over the Imperial Japanese Navy. With its capacity for aggressive action greatly diminished as a result of the Midway battle, Japan chose to focus on a belated attempt to capture Port Moresby by an Kokoda Track campaign, overland campaign in the Territory of Papua. The Americans planned a counter-attack against Japanese positions in the southern Solomon Islands, primarily Guadalcanal, as a first step towards capturing Rabaul, the main Japanese base in Southeast Asia. Both plans started in July, but by mid-September, Guadalcanal campaign, the Battle for Guadalcanal took priority for the Japanese, and troops in New Guinea were ordered to withdraw from the Port Moresby area to the Oro Province, northern part of the island, where they faced Australian and United States troops in the Battle of Buna–Gona. Guadalcanal soon became a focal point for both sides with heavy commitments of troops and ships in the battle for Guadalcanal. By the start of 1943, the Japanese were defeated on the island and Operation Ke, withdrew their troops. In Burma, Commonwealth forces mounted two operations. The first, Arakan Campaign 1942–43, an offensive into the Arakan region in late 1942, went disastrously, forcing a retreat back to India by May 1943. The second was the Chindits#Operation Longcloth, insertion of irregular forces behind Japanese front-lines in February which, by the end of April, had achieved mixed results.
Eastern Front (1942–43)Despite considerable losses, in early 1942 Germany and its allies stopped a major Soviet offensive in central and southern Russia, keeping most territorial gains they had achieved during the previous year. In May the Germans defeated Soviet offensives in the Battle of the Kerch Peninsula, Kerch Peninsula and at Second Battle of Kharkov, Kharkov, and then launched their main Case Blue, summer offensive against southern Russia in June 1942, to seize the Petroleum industry in Azerbaijan, oil fields of the Caucasus and occupy the Kuban steppe, while maintaining positions on the northern and central areas of the front. The Germans split Army Group South into two groups: Army Group A advanced to the lower Don (river), Don River and struck south-east to the Caucasus, while Army Group B headed towards the Volga, Volga River. The Soviets decided to make their stand at Stalingrad on the Volga. By mid-November, the Germans had Battle of Stalingrad, nearly taken Stalingrad in bitter urban warfare, street fighting. The Soviets began their second winter counter-offensive, starting with an Operation Uranus, encirclement of German forces at Stalingrad, and an assault on the Operation Mars, Rzhev salient near Moscow, though the latter failed disastrously. By early February 1943, the German Army had taken tremendous losses; German troops at Stalingrad had been defeated, and the front-line had been pushed back beyond its position before the summer offensive. In mid-February, after the Soviet push had tapered off, the Germans launched another Third Battle of Kharkov, attack on Kharkov, creating a Salient (military), salient in their front line around the Soviet city of Kursk.
Western Europe/Atlantic and Mediterranean (1942–43)Exploiting poor American naval command decisions, Second Happy Time, the German navy ravaged Allied shipping off the American Atlantic coast. By November 1941, Commonwealth forces had launched a counter-offensive, Operation Crusader, in North Africa, and reclaimed all the gains the Germans and Italians had made. In North Africa, the Germans launched an offensive in January, pushing the British back to positions at the Battle of Gazala#Gazala line, Gazala line by early February, followed by a temporary lull in combat which Germany used to prepare for their upcoming offensives. Concerns the Japanese might use bases in French Madagascar, Vichy-held Madagascar caused the British to Battle of Madagascar, invade the island in early May 1942. An Axis Battle of Gazala, offensive in Libya forced an Allied retreat deep inside Egypt until Axis forces were First Battle of El Alamein, stopped at El Alamein. On the Continent, raids of Allied commandos on strategic targets, culminating in the disastrous Dieppe Raid, demonstrated the Western Allies' inability to launch an invasion of continental Europe without much better preparation, equipment, and operational security. In August 1942, the Allies succeeded in repelling a Battle of Alam el Halfa, second attack against El Alamein and, at a high cost, managed to Operation Pedestal, deliver desperately needed supplies to the besieged Malta. A few months later, the Allies Second Battle of El Alamein, commenced an attack of their own in Egypt, dislodging the Axis forces and beginning a drive west across Libya. This attack was followed up shortly after by Operation Torch, Anglo-American landings in French North Africa, which resulted in the region joining the Allies. Hitler responded to the French colony's defection by ordering the Case Anton, occupation of Vichy France; although Vichy forces did not resist this violation of the armistice, they managed to Scuttling of the French fleet at Toulon, scuttle their fleet to prevent its capture by German forces. The Axis forces in Africa withdrew into Tunisia, which was Tunisian campaign, conquered by the Allies in May 1943. In June 1943 the British and Americans began Combined Bomber Offensive, a strategic bombing campaign against Germany with a goal to disrupt the war economy, reduce morale, and "dehousing, de-house" the civilian population. The Bombing of Hamburg in World War II, firebombing of Hamburg was among the first attacks in this campaign, inflicting significant casualties and considerable losses on infrastructure of this important industrial centre.
Allies gain momentum (1943–44)After the Guadalcanal Campaign, the Allies initiated several operations against Japan in the Pacific. In May 1943, Canadian and US forces were sent to Aleutian Islands campaign#Allied response, eliminate Japanese forces from the Aleutians. Soon after, the United States, with support from Australia, New Zealand and Pacific Islander forces, began major ground, sea and air operations to Operation Cartwheel, isolate Rabaul by capturing surrounding islands, and Gilbert and Marshall Islands campaign, breach the Japanese Central Pacific perimeter at the Gilbert and Marshall Islands. By the end of March 1944, the Allies had completed both of these objectives and had also Operation Hailstone, neutralised the major Japanese base at Truk in the Caroline Islands. In April, the Allies launched an operation to Western New Guinea campaign, retake Western New Guinea. In the Soviet Union, both the Germans and the Soviets spent the spring and early summer of 1943 preparing for large offensives in central Russia. On 4 July 1943, Germany Battle of Kursk, attacked Soviet forces around the Kursk Bulge. Within a week, German forces had exhausted themselves against the Soviets' deeply echeloned and well-constructed defences, and for the first time in the war Hitler cancelled the operation before it had achieved tactical or operational success. This decision was partially affected by the Western Allies' Allied invasion of Sicily, invasion of Sicily launched on 9 July, which, combined with previous Italian failures, resulted in the Fall of the Fascist regime in Italy, ousting and arrest of Mussolini later that month. On 12 July 1943, the Soviets launched their own Operation Kutuzov, counter-offensives, thereby dispelling any chance of German victory or even stalemate in the east. The Soviet victory at Kursk marked the end of German superiority, giving the Soviet Union the initiative on the Eastern Front. The Germans tried to stabilise their eastern front along the hastily fortified Panther–Wotan line, but the Soviets broke through it at Battle of Smolensk (1943), Smolensk and by the Battle of the Dnieper, Lower Dnieper Offensive. On 3 September 1943, the Western Allies Allied invasion of Italy, invaded the Italian mainland, following Armistice of Cassibile, Italy's armistice with the Allies. Germany with the help of fascists responded by Operation Achse, disarming Italian forces that were in many places without superior orders, seizing military control of Italian areas, and creating a series of defensive lines. German special forces then Gran Sasso raid, rescued Mussolini, who then soon established a new client state in German-occupied Italy named the Italian Social Republic, causing an Italian Civil War, Italian civil war. The Western Allies fought through several lines until reaching the Winter Line, main German defensive line in mid-November. German operations in the Atlantic also suffered. By Black May (1943), May 1943, as Allied counter-measures became increasingly effective, the resulting sizeable German submarine losses forced a temporary halt of the German Atlantic naval campaign. In November 1943, Franklin D. Roosevelt and Winston Churchill met with Chiang Kai-shek Cairo Conference, in Cairo and then with Joseph Stalin Tehran Conference, in Tehran.. The former conference determined the post-war return of Japanese territory. and the military planning for the Burma campaign, while the latter included agreement that the Western Allies would invade Europe in 1944 and that the Soviet Union would declare war on Japan within three months of Germany's defeat.. From November 1943, during the seven-week Battle of Changde, the Chinese forced Japan to fight a costly war of attrition, while awaiting Allied relief... In January 1944, the Allies launched a Battle of Monte Cassino, series of attacks in Italy against the line at Monte Cassino and tried to outflank it with Battle of Anzio, landings at Anzio. On 27 January 1944, Leningrad Front, Soviet troops launched Siege of Leningrad#Soviet relief of the siege, a major offensive that expelled German forces from the Leningrad Oblast, Leningrad region, thereby ending the List of battles by casualties#Sieges and urban combat, most lethal siege in history.. The Leningrad–Novgorod Offensive, following Soviet offensive was Battle of Narva (1944), halted on the pre-war Estonian border by the German Army Group North aided by German occupation of Estonia during World War II#Estonians in Nazi German military units, Estonians hoping to Estonian government-in-exile#Failure to reestablish independence, re-establish national independence. This delay slowed subsequent Soviet operations in the Baltic Sea region.. By late May 1944, the Soviets had Crimean Offensive, liberated Crimea, Dnieper–Carpathian Offensive, largely expelled Axis forces from Ukraine, and made First Jassy–Kishinev Offensive, incursions into Romania, which were repulsed by the Axis troops.. The Allied offensives in Italy had succeeded and, at the expense of allowing several German divisions to retreat, on 4 June Rome was captured. The Allies had mixed success in mainland Asia. In March 1944, the Japanese launched the first of two invasions, Operation U-Go, an operation against British positions in Assam, India,. and soon besieged Commonwealth positions at Battle of Imphal, Imphal and Battle of Kohima, Kohima.. In May 1944, British forces mounted a counter-offensive that drove Japanese troops back to Burma by July, and Chinese forces that had Battle of Northern Burma and Western Yunnan, invaded northern Burma in late 1943 Siege of Myitkyina, besieged Japanese troops in Myitkyina. The Operation Ichi-Go, second Japanese invasion of China aimed to destroy China's main fighting forces, secure railways between Japanese-held territory and capture Allied airfields. By June, the Japanese had conquered the province of Henan and begun a Battle of Changsha (1944), new attack on Changsha.
Allies close in (1944)On 6 June 1944 (known as Normandy landings, D-Day), after three years of Soviet pressure,: "Stalin always believed that Britain and America were delaying the second front so that the Soviet Union would bear the brunt of the war." the Western Allies Operation Overlord, invaded northern France. After reassigning several Allied divisions from Italy, they also Operation Dragoon, attacked southern France.. These landings were successful and led to the defeat of the Falaise Pocket, German Army units in France. Paris was Liberation of Paris, liberated on 25 August by the French Resistance, local resistance assisted by the Free French Forces, both led by General Charles de Gaulle, and the Western Allies continued to Allied advance from Paris to the Rhine, push back German forces in western Europe during the latter part of the year. An attempt to advance into northern Germany spearheaded by Operation Market Garden, a major airborne operation in the Netherlands failed. After that, the Western Allies slowly pushed into Germany, but Operation Queen, failed to cross the Rur river in a large offensive. In Italy, Allied advance also slowed due to the Gothic Line, last major German defensive line. On 22 June, the Soviets launched a strategic offensive in Belarus ("Operation Bagration") that almost completely destroyed the German Army Group Centre.: "It was the most calamitous defeat of all the German armed forces in World War II." Soon after that, Lvov–Sandomierz Offensive, another Soviet strategic offensive forced German troops from Western Ukraine and Eastern Poland. The Soviets formed the Polish Committee of National Liberation to control territory in Poland and combat the Polish Home Army, Armia Krajowa; The Soviet Red Army remained in the Praga district on the other side of the Vistula and watched passively as the Germans quelled the Warsaw Uprising initiated by the Armia Krajowa. The Slovak National Uprising, national uprising in Slovak Republic (1939–1945), Slovakia was also quelled by the Germans. The Soviet Red Army's Second Jassy–Kishinev Offensive, strategic offensive in eastern Romania cut off and destroyed the Army Group South Ukraine, considerable German troops there and triggered King Michael's Coup, a successful coup d'état in Romania and 1944 Bulgarian coup d'état, in Bulgaria, followed by those countries' shift to the Allied side. In September 1944, Soviet troops advanced into Democratic Federal Yugoslavia, Yugoslavia and forced the rapid withdrawal of German Army Groups Army Group E, E and Army Group F, F in Axis occupation of Greece, Greece, German occupation of Albania, Albania and Yugoslavia to rescue them from being cut off.. By this point, the Communist-led Yugoslav Partisans, Partisans under Marshal Josip Broz Tito, who had led an World War II in Yugoslavia, increasingly successful guerrilla campaign against the occupation since 1941, controlled much of the territory of Yugoslavia and engaged in delaying efforts against German forces further south. In northern Territory of the Military Commander in Serbia, Serbia, the Soviet Red Army, with limited support from Bulgarian forces, assisted the Partisans in a joint Belgrade Offensive, liberation of the capital city of Belgrade on 20 October. A few days later, the Soviets launched a Budapest Offensive, massive assault against Operation Panzerfaust, German-occupied Hungary that lasted until Siege of Budapest, the fall of Budapest in February 1945. Unlike impressive Soviet victories in the Balkans, Continuation War, bitter Finnish resistance to the Vyborg–Petrozavodsk Offensive, Soviet offensive in the Karelian Isthmus denied the Soviets occupation of Finland and led to a Moscow Armistice, Soviet-Finnish armistice on relatively mild conditions, although Finland was forced to Lapland War, fight their former ally Germany. By the start of July 1944, Commonwealth forces in Southeast Asia had repelled the Japanese sieges in Assam, pushing the Japanese back to the Chindwin River. while the Chinese captured Myitkyina. In September 1944, Chinese forces Battle of Mount Song, captured Mount Song and reopened the Burma Road. In China, the Japanese had more successes, having finally Battle of Changsha (1944)#Battle of Changsha, captured Changsha in mid-June and the city of Defense of Hengyang, Hengyang by early August. Soon after, they invaded the province of Guangxi, winning major engagements against Chinese forces at Battle of Guilin–Liuzhou, Guilin and Liuzhou by the end of November and successfully linking up their forces in China and Indochina by mid-December.. In the Pacific, US forces continued to press back the Japanese perimeter. In mid-June 1944, they began their Mariana and Palau Islands campaign, offensive against the Mariana and Palau islands and decisively defeated Japanese forces in the Battle of the Philippine Sea. These defeats led to the resignation of the Japanese Prime Minister, Hideki Tojo, and provided the United States with air bases to launch intensive heavy bomber attacks on the Japanese home islands. In late October, American forces Battle of Leyte, invaded the Filipino island of Leyte; soon after, Allied naval forces scored another large victory in the Battle of Leyte Gulf, one of the largest naval battles in history.
Axis collapse, Allied victory (1944–45)On 16 December 1944, Germany made a last attempt on the Western Front by using most of its remaining reserves to launch Battle of the Bulge, a massive counter-offensive in the Ardennes and Operation Nordwind, along with the French-German border to split the Western Allies, encircle large portions of Western Allied troops and capture their primary supply port at Antwerp to prompt a political settlement. By January, the offensive had been repulsed with no strategic objectives fulfilled. In Italy, the Western Allies remained stalemated at the German defensive line. In mid-January 1945, the Red Army attacked in Poland, Vistula–Oder Offensive, pushing from the Vistula to the Oder river in Germany, and East Prussian Offensive, overran East Prussia. On 4 February Soviet, British, and US leaders met for the Yalta Conference. They agreed on the occupation of post-war Germany, and on when the Soviet Union would join the war against Japan. In February, the Soviets Silesian Offensives, entered Silesia and East Pomeranian Offensive, Pomerania, while Western Allied invasion of Germany, Western Allies entered western Germany and closed to the Rhine river. By March, the Western Allies crossed the Rhine Operation Plunder, north and Remagen, south of the Rhine-Ruhr, Ruhr, Ruhr Pocket, encircling the German Army Group B. In early March, in an attempt to protect its last oil reserves in Hungary and to retake Budapest, Germany launched Operation Spring Awakening, its last major offensive against Soviet troops near Lake Balaton. In two weeks, the offensive had been repulsed, the Soviets advanced to Vienna offensive, Vienna, and captured the city. In early April, Soviet troops Battle of Königsberg, captured Königsberg, while the Western Allies finally Spring 1945 offensive in Italy, pushed forward in Italy and swept across western Germany capturing Battle of Hamburg (1945), Hamburg and Battle of Nuremberg (1945), Nuremberg. Elbe Day, American and Soviet forces met at the Elbe river on 25 April, leaving several unoccupied pockets in southern Germany and around Berlin. Soviet troops Battle of Berlin, stormed and captured Berlin in late April. In Italy, Surrender of Caserta, German forces surrendered on 29 April. On 30 April, the Reichstag building, Reichstag was captured, signalling the military defeat of Nazi Germany, and the Berlin garrison surrendered on 2 May. Several changes in leadership occurred during this period. On 12 April, President Roosevelt died and was succeeded by Harry S. Truman. Benito Mussolini Death of Benito Mussolini, was killed by Italian resistance movement, Italian partisans on 28 April.. Two days later, Death of Adolf Hitler, Hitler committed suicide in besieged Berlin, and he was succeeded by Grand Admiral Karl Dönitz. German Instrument of Surrender, Total and unconditional surrender in Europe was signed Victory in Europe Day, on 7and 8May, to be effective by the end of Victory Day (Eastern Front), 8 May.. German Army Group Centre Prague Offensive, resisted in Prague until 11 May.. In the Pacific theatre, American forces accompanied by the forces of the Philippine Commonwealth advanced Philippines campaign (1944–1945), in the Philippines, Battle of Leyte, clearing Leyte by the end of April 1945. They Battle of Luzon, landed on Luzon in January 1945 and Battle of Manila (1945), recaptured Manila in March. Fighting continued on Luzon, Battle of Mindanao, Mindanao, and other islands of the Philippines until the End of World War II in Asia, end of the war. Meanwhile, the United States Army Air Forces launched Air raids on Japan, a massive firebombing campaign of strategic cities in Japan in an effort to destroy Japanese war industry and civilian morale. A devastating Bombing of Tokyo, bombing raid on Tokyo of 9–10 March was the deadliest conventional bombing raid in history. In May 1945, Australian troops Borneo campaign, landed in Borneo, overrunning the oilfields there. British, American, and Chinese forces defeated the Japanese in northern Burma campaign, Burma in March, and the British pushed on to reach Yangon, Rangoon by 3 May.. Chinese forces started a counterattack in the Battle of West Hunan that occurred between 6 April and 7 June 1945. American naval and amphibious forces also moved towards Japan, taking Battle of Iwo Jima, Iwo Jima by March, and Battle of Okinawa, Okinawa by the end of June. At the same time, American submarines Allied submarines in the Pacific War, cut off Japanese imports, drastically reducing Japan's ability to supply its overseas forces. On 11 July, Allied leaders Potsdam Conference, met in Potsdam, Germany. They Potsdam Agreement, confirmed earlier agreements about Germany,. and the American, British and Chinese governments reiterated the demand for unconditional surrender of Japan, specifically stating that Potsdam Declaration, "the alternative for Japan is prompt and utter destruction".. During this conference, the United Kingdom 1945 United Kingdom general election, held its general election, and Clement Attlee replaced Churchill as Prime Minister.. The call for unconditional surrender was rejected by the Japanese government, which believed it would be capable of negotiating for more favourable surrender terms. In early August, the United States Atomic bombings of Hiroshima and Nagasaki, dropped atomic bombs on the Japanese cities of and . Between the two bombings, the Soviets, pursuant to the Yalta agreement, Soviet invasion of Manchuria, invaded Japanese-held Manchuria and quickly defeated the Kwantung Army, which was the largest Japanese fighting force. These two events persuaded previously adamant Imperial Army leaders to accept surrender terms. " The principal cause of Japan's surrender was the ability of the United States to increase the military vulnerability of Japan's home islands, persuading Japanese leaders that defense of the homeland was highly unlikely to succeed. The key military factor causing this effect was the sea blockade, which crippled Japan's ability to produce and equip the forces necessary to execute its strategy. The most important factor accounting for the timing of surrender was the Soviet attack against Manchuria, largely because it persuaded previously adamant Army leaders that the homeland could not be defended.". The Red Army also captured the Soviet Invasion of South Sakhalin, southern part of Sakhalin Island and the Invasion of the Kuril Islands, Kuril Islands. On 15 August 1945, Surrender of Japan, Japan surrendered, with the Japanese Instrument of Surrender, surrender documents finally signed at Tokyo Bay on the deck of the American battleship USS Missouri (BB-63), USS ''Missouri'' on 2 September 1945, ending the war..
AftermathThe Allies established occupation administrations in Allied-occupied Austria, Austria and . The former became a neutral state, non-aligned with any political bloc. The latter was divided into western and eastern occupation zones controlled by the Western Allies and the Soviet Union. A denazification programme in Germany led to the prosecution of Nazi war criminals in the Nuremberg trials and the removal of ex-Nazis from power, although this policy moved towards amnesty and re-integration of ex-Nazis into West German society.. Germany lost a quarter of its pre-war (1937) territory. Among the eastern territories, Silesia, Neumark and most of Pomerania were taken over by Poland, and East Prussia was divided between Poland and the Soviet Union, followed by the Flight and expulsion of Germans (1944–50), expulsion to Germany of the nine million Germans from these provinces, as well as three million Germans from the Sudetenland in Czechoslovakia. By the 1950s, one-fifth of West Germans were refugees from the east. The Soviet Union also took over the Polish provinces east of the Curzon line, from which Polish population transfers (1944–1946), 2 million Poles were expelled;. north-east Romania,.. parts of eastern Finland,. and the three Baltic states were Soviet occupation of the Baltic states (1944), incorporated into the Soviet Union... In an effort to maintain world peace,. the Allies formed the , which officially came into existence on 24 October 1945, and adopted the Universal Declaration of Human Rights in 1948 as a common standard for all Member states of the United Nations, member nations. .
Casualties and war crimesEstimates for the total number of casualties in the war vary, because many deaths went unrecorded. Most suggest that some 60 million people died in the war, including about Battle casualties of World War II, 20 million military personnel and 40 million civilians. Many of the civilians died because of deliberate , List of massacres, massacres, Strategic bombing during World War II, mass bombings, Infectious disease, disease, and . The Soviet Union alone lost around 27 million people during the war, including 8.7 million military and 19 million civilian deaths.. A quarter of the total people in the Soviet Union were wounded or killed. Germany sustained 5.3 million military losses, mostly on the Eastern Front and during the final battles in Germany.. An estimated 11 to 17 million. civilians died as a direct or as an indirect result of Hitler's Racial policy of Nazi Germany, racist policies, including mass killing of the Holocaust, around 6million Jews, along with Romani genocide, Roma, Persecution of homosexuals in Nazi Germany and the Holocaust, homosexuals, at least 1.9 million ethnic World War II casualties of Poland, Poles and World War II casualties of the Soviet Union, millions of other Slavs (including Russians, Ukrainians and Belarusians), and Holocaust victims, other ethnic and minority groups. Between 1941 and 1945, more than 200,000 ethnic Serbs, along with gypsies and Jews, were Persecution of Serbs in the Independent State of Croatia, persecuted and murdered by the Axis-aligned Croatian Ustaše in Yugoslavia. Concurrently, Bosniaks, Muslims and Croats were Chetnik war crimes in World War II, persecuted and killed by Serb nationalist Chetniks, with an estimated 50,000-68,000 victims (of which 41,000 were civilians).. Also, more than 100,000 Poles were massacred by the Ukrainian Insurgent Army in the Massacres of Poles in Volhynia and Eastern Galicia, Volhynia massacres, between 1943 and 1945. At the same time, about 10,000–15,000 Ukrainians were killed by the Polish Home Army and other Polish units, in reprisal attacks. In Asia and the Pacific, between 3million and more than 10 million civilians, mostly Chinese (estimated at 7.5 million), were killed by the Japanese occupation forces. The most infamous Japanese atrocity was the Nanking Massacre, in which fifty to three hundred thousand Chinese civilians were raped and murdered. Mitsuyoshi Himeta reported that 2.7 million casualties occurred during the ''Three Alls Policy, Sankō Sakusen''. General Yasuji Okamura implemented the policy in Heipei and Shantung. Axis forces employed Biological warfare, biological and Chemical warfare, chemical weapons. The Imperial Japanese Army used a variety of such weapons during its Second Sino-Japanese War, invasion and occupation of China (''see Unit 731'') and in Battles of Khalkhin Gol, early conflicts against the Soviets. Both the Germans and the Japanese human experimentation on the Chinese, Japanese tested such weapons against civilians, and sometimes on prisoner of war, prisoners of war. The Soviet Union was responsible for the Katyn massacre of 22,000 Polish officers, and the imprisonment or execution of NKVD prisoner massacres, thousands of political prisoners by the NKVD, along with Population transfer in the Soviet Union, mass civilian deportations to Siberia, in the and Territories of Poland annexed by the Soviet Union, eastern Poland annexed by the Red Army. The mass bombing of cities in Europe and Asia has often been called a war crime, although no Positive international law, positive or specific Customary international law, customary international humanitarian law with respect to aerial warfare existed before or during World War II. The USAAF Air raids on Japan, firebombed a total of 67 Japanese cities, killing 393,000 civilians and destroying 65% of built-up areas.
Genocide, concentration camps, and slave labour, under the dictatorship of Adolf Hitler, was responsible for (which killed approximately 6million Jews) as well as for Nazi crimes against the Polish nation, killing 2.7 million ethnic Poles and 4million others who were deemed "life unworthy of life, unworthy of life" (including the Disability, disabled and Mental disorder, mentally ill, German mistreatment of Soviet prisoners of war, Soviet prisoners of war, Romani people, Romani, homosexuals, Freemasons, and Jehovah's Witnesses) as part of a programme of deliberate extermination, in effect becoming a "genocidal state". German mistreatment of Soviet prisoners of war, Soviet POWs were kept in especially unbearable conditions, and 3.6 million Soviet POWs out of 5.7 million died in Nazi camps during the war.. In addition to Nazi concentration camps, concentration camps, Extermination camp, death camps were created in Nazi Germany to exterminate people on an industrial scale. Nazi Germany extensively used Forced labour under German rule during World War II, forced labourers; about 12 million Ostarbeiter, Europeans from German-occupied countries were abducted and used as a slave work force in German industry, agriculture and war economy. The Soviet Gulag became a ''de facto'' system of deadly camps during 1942–43, when wartime privation and hunger caused numerous deaths of inmates, including foreign citizens of Poland and Occupation of Baltic States, other countries occupied in 1939–40 by the Soviet Union, as well as Axis German prisoners of war in the Soviet Union, POWs. By the end of the war, most Soviet POWs liberated from Nazi camps and many repatriated civilians were detained in special filtration camps where they were subjected to NKVD evaluation, and 226,127 were sent to the Gulag as real or perceived Nazi collaborators. Japanese prisoner-of-war camps, many of which were used as labour camps, also had high death rates. The International Military Tribunal for the Far East found the death rate of Western prisoners was 27 per cent (for American POWs, 37 per cent), seven times that of POWs under the Germans and Italians. While 37,583 prisoners from the UK, 28,500 from the Netherlands, and 14,473 from the United States were released after the , the number of Chinese released was only 56. At least five million Chinese civilians from northern China and Manchukuo were enslaved between 1935 and 1941 by the East Asia Development Board, or ''Kōain'', for work in mines and war industries. After 1942, the number reached 10 million. In Java, between 4and 10 million ''rōmusha'' (Japanese: "manual labourers"), were forced to work by the Japanese military. About 270,000 of these Javanese labourers were sent to other Japanese-held areas in South East Asia, and only 52,000 were repatriated to Java.
OccupationIn Europe, occupation came under two forms. In Western, Northern, and Central Europe (France, Norway, Denmark, the Low Countries, and the Protectorate of Bohemia and Moravia, annexed portions of Czechoslovakia) Germany established economic policies through which it collected roughly 69.5 billion reichsmarks (27.8 billion US dollars) by the end of the war; this figure does not include the Nazi plunder, sizeable plunder of industrial products, military equipment, raw materials and other goods. Thus, the income from occupied nations was over 40 percent of the income Germany collected from taxation, a figure which increased to nearly 40 percent of total German income as the war went on.. In the East, the intended gains of ''Lebensraum'' were never attained as fluctuating front-lines and Soviet scorched earth policies denied resources to the German invaders.. Unlike in the West, the Racial policy of Nazi Germany, Nazi racial policy encouraged extreme brutality against what it considered to be the "Untermensch, inferior people" of Slavic descent; most German advances were thus followed by Generalplan Ost, mass executions. Although Resistance during World War II, resistance groups formed in most occupied territories, they did not significantly hamper German operations in either the East or the West until late 1943. In Asia, Japan termed nations under its occupation as being part of the Greater East Asia Co-Prosperity Sphere, essentially a Japanese hegemony which it claimed was for purposes of liberating colonised peoples. Although Japanese forces were sometimes welcomed as liberators from European domination, Japanese war crimes frequently turned local public opinion against them.. During Japan's initial conquest, it captured of oil (~550,000 tonnes) left behind by retreating Allied forces; and by 1943, was able to get production in the Dutch East Indies up to of oil (~6.8 million tonnes), 76 per cent of its 1940 output rate.
Home fronts and productionIn Europe, before the outbreak of the war, the Allies had significant advantages in both population and economics. In 1938, the Western Allies (United Kingdom, France, Poland and the British Dominions) had a 30 percent larger population and a 30 percent higher gross domestic product than the European Axis powers (Germany and Italy); if colonies are included, the Allies had more than a 5:1 advantage in population and a nearly 2:1 advantage in GDP.. In Asia at the same time, China had roughly six times the population of Japan but only an 89 percent higher GDP; this is reduced to three times the population and only a 38 percent higher GDP if Japanese colonies are included. The United States produced about two-thirds of all the munitions used by the Allies in WWII, including warships, transports, warplanes, artillery, tanks, trucks, and ammunition. Though the Allies' economic and population advantages were largely mitigated during the initial rapid blitzkrieg attacks of Germany and Japan, they became the decisive factor by 1942, after the United States and Soviet Union joined the Allies, as the war largely settled into one of Attrition warfare, attrition.. While the Allies' ability to out-produce the Axis is often attributed to the Allies having more access to natural resources, other factors, such as Germany and Japan's reluctance to employ women in the labour force, Allied Strategic bombing during World War II, strategic bombing, and Germany's late shift to a war economy contributed significantly. Additionally, neither Germany nor Japan planned to fight a protracted war, and had not equipped themselves to do so. To improve their production, Germany and Japan used millions of slave labourers; Forced labour under German rule during World War II, Germany used about 12 million people, mostly from Eastern Europe, while Slavery in Japan, Japan used more than 18 million people in Far East Asia.
Advances in technology and warfareAircraft were used for Reconnaissance aircraft, reconnaissance, as fighter aircraft, fighters, bombers, and close air support, ground-support, and each role was advanced considerably. Innovation included airlift (the capability to quickly move limited high-priority supplies, equipment, and personnel);. and of (the bombing of enemy industrial and population centres to destroy the enemy's ability to wage war). Anti-aircraft warfare, Anti-aircraft weaponry also advanced, including defences such as radar and surface-to-air artillery. The use of the jet aircraft was pioneered and, though late introduction meant it had little impact, it led to jets becoming standard in air forces worldwide. Although Missile, guided missiles were being developed, they were not advanced enough to reliably Surface-to-air missile, target aircraft until some years after the war. Advances were made in nearly every aspect of naval warfare, most notably with aircraft carriers and submarines. Although Aeronautics, aeronautical warfare had relatively little success at the start of the war, Battle of Taranto, actions at Taranto, Attack on Pearl Harbor, Pearl Harbor, and the Battle of the Coral Sea, Coral Sea established the carrier as the dominant capital ship in place of the battleship.. In the Atlantic, escort carriers proved to be a vital part of Allied convoys, increasing the effective protection radius and helping to close the Mid-Atlantic gap. Carriers were also more economical than battleships because of the relatively low cost of aircraft and their not requiring to be as heavily armoured. Submarines, which had proved to be an effective weapon during the World War I, First World War,. were anticipated by all sides to be important in the second. The British focused development on Anti-submarine warfare, anti-submarine anti-submarine weapon, weaponry and tactics, such as sonar and convoys, while Germany focused on improving its offensive capability, with designs such as the German Type VII submarine, Type VII submarine and Wolfpack (naval tactic), wolfpack tactics.. Gradually, improving Allied technologies such as the Leigh light, Hedgehog (weapon), hedgehog, Squid (weapon), squid, and Mark 24 mine, homing torpedoes proved victorious over the German submarines. Land warfare changed from the static front lines of trench warfare of World War I, which had relied on improved artillery that outmatched the speed of both infantry and cavalry, to increased mobility and combined arms. The tank, which had been used predominantly for infantry support in the First World War, had evolved into the primary weapon.. In the late 1930s, tank design was considerably more advanced than it had been during World WarI, and Tanks in World War II, advances continued throughout the war with increases in speed, armour and firepower. At the start of the war, most commanders thought enemy tanks should be met by tanks with superior specifications.. This idea was challenged by the poor performance of the relatively light early tank guns against armour, and German doctrine of avoiding tank-versus-tank combat. This, along with Germany's use of combined arms, were among the key elements of their highly successful blitzkrieg tactics across Poland and France. Many means of anti-tank warfare, destroying tanks, including Indirect fire, indirect artillery, anti-tank guns (both towed and self-propelled gun, self-propelled), anti-tank mine, mines, short-ranged infantry antitank weapons, and other tanks were used. Even with large-scale mechanisation, infantry remained the backbone of all forces,. and throughout the war, most infantry were equipped similarly to World War I.. The portable machine gun spread, a notable example being the German MG34, and various submachine guns which were suited to close combat in urban and jungle settings. The assault rifle, a late war development incorporating many features of the rifle and submachine gun, became the standard postwar infantry weapon for most armed forces. Most major belligerents attempted to solve the problems of complexity and security involved in using large codebooks for cryptography by designing ciphering machines, the most well known being the German Enigma machine. Development of SIGINT (''sig''nals ''int''elligence) and cryptanalysis enabled the countering process of decryption. Notable examples were the Allied decryption of Japanese naval codes and British Ultra, a Bombe#The British Bombe, pioneering method for decoding Enigma benefiting from information given to the United Kingdom by the Polish Cipher Bureau#Gift to allies, Polish Cipher Bureau, which had been decoding early versions of Enigma before the war. Another aspect of military intelligence was the use of deception, which the Allies used to great effect, such as in operations Operation Mincemeat, Mincemeat and Operation Bodyguard, Bodyguard. Other technological and engineering feats achieved during, or as a result of, the war include the world's first programmable computers (Z3 (computer), Z3, Colossus computer, Colossus, and ENIAC), V-1 flying bomb, guided missiles and V-2 rocket, modern rockets, the Manhattan Project's development of
See also* Index of World War II articles * Lists of World War II topics * Outline of World War II
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