Debate over the atomic bombings of Hiroshima and Nagasaki

Substantial debate exists over the ethical, legal, and military aspects of the atomic bombings of Hiroshima and Nagasaki on 6 August and 9 August 1945 at the close of World War II (1939–45).

On 26 July 1945, United States President Harry S. Truman, British Prime Minister Winston Churchill and President of China Chiang Kai-shek issued the Potsdam Declaration, which outlined the terms of surrender for the Empire of Japan as agreed upon at the Potsdam Conference. This ultimatum stated if Japan did not surrender, it would face "prompt and utter destruction". Some debaters focus on the presidential decision-making process, and others on whether or not the bombings were the proximate cause of Japanese surrender.

Over the course of time, different arguments have gained and lost support as new evidence has become available and as new studies have been completed. A primary and continuing focus has been on whether the bombing should be categorized as a war crime or as a crime against humanity. There is also the debate on the role of the bombings in Japan's surrender and the U.S.'s justification for them based upon the premise that the bombings precipitated the surrender. This remains the subject of both scholarly and popular debate, with revisionist historians advancing a variety of arguments. In 2005, in an overview of historiography about the matter, J. Samuel Walker wrote, "the controversy over the use of the bomb seems certain to continue". Walker stated, "The fundamental issue that has divided scholars over a period of nearly four decades is whether the use of the bomb was necessary to achieve victory in the war in the Pacific on terms satisfactory to the United States.".

Supporters of the bombings generally assert that they caused the Japanese surrender, preventing massive casualties on both sides in the planned invasion of Japan: Kyūshū was to be invaded in November 1945 and Honshū four months later. It was thought Japan would not surrender unless there was an overwhelming demonstration of destructive capability. Those who oppose the bombings argue it was militarily unnecessary, inherently immoral, a war crime, or a form of state terrorism. Critics believe a naval blockade and conventional bombings would have forced Japan to surrender unconditionally. Some critics believe Japan was more motivated to surrender by the Soviet Union's invasion of Manchuria and other Japanese-held areas.

Support

Prevention of many U.S. and Japanese military casualties

Those who argue in favor of the decision to drop the atomic bombs on enemy targets believe massive casualties on both sides would have occurred in Operation Downfall, the planned Allied invasion of Japan. The bulk of the force invading Japan would be American although the British Commonwealth would contribute three divisions of troops (one each from the United Kingdom, Canada, and Australia).

The U.S. anticipated losing many combatants in Downfall, although the number of expected fatalities and wounded is subject to some debate. U.S. President Harry S. Truman stated in 1953 he had been advised U.S. casualties could range from 250,000 to one million combatants. Assistant Secretary of the Navy Ralph Bard, a member of the Interim Committee on atomic matters, stated that while meeting with Truman in the summer of 1945 they discussed the bomb's use in the context of massive combatant and non-combatant casualties from invasion, with Bard raising the possibility of a million Allied combatants being killed. As Bard opposed using the bomb without warning Japan first, he cannot be accused of exaggerating casualty expectations to justify the bomb's use, and his account is evidence that Truman was aware of, and government officials discussed, the possibility of one million casualties.. However, other estimates were lower. For example, on June 18, 1945, General Douglas MacArthur, the commander of the invasion force, predicted 95,000 casualties (a third of those deaths) in the first 90 days of the invasion.

A quarter of a million casualties is roughly the level the Joint War Plans Committee estimated, in its paper (JWPC 369/1) prepared for Truman's 18 June meeting. A review of documents from the Truman Library shows Truman's initial draft response to the query describes Marshall only as saying "one quarter of a million would be the minimum". The "as much as a million" phrase was added to the final draft by Truman's staff, so as not to appear to contradict an earlier statement given in a published article by Stimson (former Secretary of War). In a study done by the Joint Chiefs of Staff in April 1945, the figures of 7.45 casualties per 1,000 man-days and 1.78 fatalities per 1,000 man-days were developed. This implied the two planned campaigns to conquer Japan would cost 1.6 million U.S. casualties, including 380,000 dead. JWPC 369/1 (prepared June 15, 1945) which provided planning information to the Joint Chiefs of Staff, estimated an invasion of Japan would result in 40,000 U.S. dead and 150,000 wounded. Delivered on June 15, 1945, after insight gained from the Battle of Okinawa, the study noted Japan's inadequate defenses resulting from a very effective sea blockade and the Allied firebombing campaign. Generals George C. Marshall and Douglas MacArthur signed documents agreeing with the Joint War Plans Committee estimate.

In addition, a large number of Japanese combatant and non-combatant casualties were expected as a result of such actions. Contemporary estimates of Japanese deaths from an invasion of the Home Islands range from several hundreds of thousands to as high as ten million. General MacArthur's staff provided an estimated range of American deaths depending on the duration of the invasion, and also estimated a 22:1 ratio of Japanese to American deaths. From this, a low figure of somewhat more than 200,000 Japanese deaths can be calculated for a short invasion of two weeks, and almost three million Japanese deaths if the fighting lasted four months. A widely cited estimate of five to ten million Japanese deaths came from a study by William Shockley and Quincy Wright; the upper figure was used by Assistant Secretary of War John J. McCloy, who characterized it as conservative. Some 400,000 additional Japanese deaths might have occurred in the expected Soviet invasion of Hokkaido, the northernmost of Japan's main islands, An Air Force Association webpage states that "Millions of women, old men, and boys and girls had been trained to resist by such means as attacking with bamboo spears and strapping explosives to their bodies and throwing themselves under advancing tanks." The AFA noted that " e Japanese cabinet had approved a measure extending the draft to include men from ages fifteen to sixty and women from seventeen to forty-five (an additional 28 million people)".

The great loss of life during the battle of Iwo Jima and other Pacific islands gave U.S. leaders an idea of the casualties that would happen with a mainland invasion. Of the 22,060 Japanese combatants entrenched on Iwo Jima, 21,844 died either from fighting or by ritual suicide. Only 216 Japanese POWs were held at the hand of the Americans during the battle. According to the official Navy Department Library website, "The 36-day (Iwo Jima) assault resulted in more than 26,000 American casualties, including 6,800 dead" with 19,217 wounded., talks about how many historians have overestimated the number Japanese defenders, with 20,000 and even 25,000 listed. Burrell puts the range between 18,061 and 18,591, with exactly 216 of these taken prisoner. The rest were KIA or MIA. To put this into context, the 82-day Battle of Okinawa lasted from early April until mid-June 1945 and U.S. casualties (out of five Army and two Marine divisions) were above 62,000, of which more than 12,000 were killed or missing.

The U.S. military had nearly 500,000 Purple Heart medals manufactured in anticipation of potential casualties from the planned invasion of Japan. To date, all American military casualties of the 60 years following the end of World War II, including the Korean and Vietnam Wars, have not exceeded that number. In 2003, there were still 120,000 of these Purple Heart medals in stock.Giangreco, Dennis M. & Moore, Kathryn
"Are New Purple Hearts Being Manufactured to Meet the Demand?"
''History News Network'' (December 1, 2003), Retrieved December 4, 2006 Because of the number available, combat units in Iraq and Afghanistan were able to keep Purple Hearts on hand for immediate award to wounded soldiers on the field.

Expedited end of war saved lives

Supporters of the bombings argue waiting for the Japanese to surrender would also have cost lives. "For China alone, depending upon what number one chooses for overall Chinese casualties, in each of the ninety-seven months between July 1937 and August 1945, somewhere between 100,000 and 200,000 persons perished, the vast majority of them noncombatants. For the other Asian states alone, the average probably ranged in the tens of thousands per month, but the actual numbers were almost certainly greater in 1945, notably due to the mass death in a famine in Vietnam."

The end of the war limited the expansion of the Japanese controlled Vietnamese famine of 1945, stopping it at 1–2 million deaths and also liberated millions of Allied prisoners of war and civilian laborers working in harsh conditions under a forced mobilization. In the Dutch East Indies, there was a "forced mobilization of some 4 million—although some estimates are as high as 10 million—''romusha'' (manual labourers) ... About 270,000 romusha were sent to the Outer Islands and Japanese-held territories in Southeast Asia, where they joined other Asians in performing wartime construction projects. At the end of the war, only 52,000 were repatriated to Java."

Supporters also point to an order given by the Japanese War Ministry on August 1, 1944, ordering the execution of Allied POWs, "when an uprising of large numbers cannot be suppressed without the use of firearms" or when the POW camp was in the combat zone, in fear that "escapees from the camp may turn into a hostile fighting force"., The only existing original copy of this general order was found by Jack Edwards after the war, in the ruins of the Kinkaseki prisoner of war camp in Formosa. ( Edwards p. 260)

The ''Operation Meetinghouse'' firebombing raid on Tokyo alone killed 100,000 civilians on the night of March 9–10, 1945, causing more civilian death and destruction than either of the atomic bombs dropped on Hiroshima and Nagasaki. A total of 350,000 civilians died in the incendiary raids on 67 Japanese cities. Because the United States Army Air Forces wanted to use its fission bombs on previously undamaged cities in order to have accurate data on nuclear-caused damage, Kokura, Hiroshima, Nagasaki, and Niigata were preserved from conventional bombing raids. Otherwise, they would all have been firebombed. Intensive conventional bombing would have continued or increased prior to an invasion. The submarine blockade and the United States Army Air Forces's mining operation, Operation Starvation, had effectively cut off Japan's imports. A complementary operation against Japan's railways was about to begin, isolating the cities of southern Honshū from the food grown elsewhere in the Home Islands. "Immediately after the defeat, some estimated that 10 million people were likely to starve to death", noted historian Daikichi Irokawa. Meanwhile, fighting continued in the Philippines, New Guinea and Borneo, and offensives were scheduled for September in southern China and Malaya. The Soviet invasion of Manchuria had, in the week before the surrender, caused over 80,000 deaths.

In September 1945, nuclear physicist Karl Taylor Compton, who himself took part in the Manhattan Project, visited MacArthur's headquarters in Tokyo, and following his visit wrote a defensive article, in which he summarized his conclusions as follows:

Philippine justice Delfín Jaranilla, member of the Tokyo tribunal, wrote in his judgment:

Lee Kuan Yew, the Former Prime Minister of Singapore concurred:

Lee witnessed his home city being invaded by the Japanese and was nearly executed in the Sook Ching Massacre.

Part of total war

Supporters of the bombings have argued the Japanese government had promulgated a National Mobilization Law and waged total war, ordering many civilians (including women, children, and old people) to work in factories and other infrastructure attached to the war effort and to fight against any invading force. Unlike the United States and Nazi Germany, over 90% of the Japanese war production was done in unmarked workshops and cottage industries which were widely dispersed within residential areas in cities and thus making them more extensively difficult to find and attack. In addition, the dropping of high explosives with precision bombing was unable to penetrate Japan's dispersed industry, making it entirely impossible to destroy them without causing widespread damage to surrounding areas. General Curtis LeMay stated why he ordered the systematic carpet bombing of Japanese cities:

For six months prior to the combat use of nuclear weapons, the United States Army Air Forces under LeMay's command undertook a major strategic bombing campaign against Japanese cities through the use of incendiary bombs, destroying 67 cities and killing an estimated 350,000 civilians. The ''Operation Meetinghouse'' raid on Tokyo on the night of 9/10 March 1945 stands as the deadliest air raid in human history, killing 100,000 civilians and destroying of the city that night. The attack caused more civilian deaths and damage to urbanized land than any other single air attack, including the atomic bombings of Hiroshima and Nagasaki combined.

Colonel Harry F. Cunningham, an intelligence officer of the Fifth Air Force, noted that in addition to civilians producing weapons of war in cities, the Japanese government created a large civilian militia organization in order to train millions of civilians to be armed and to resist the American invaders. In his official intelligence review on July 21, 1945, he declared that:

Supporters of the bombings have emphasized the strategic significance of the targets. Hiroshima was used as headquarters of the Second General Army and Fifth Division, which commanded the defense of southern Japan with 40,000 combatants stationed in the city. The city was also a communication center, an assembly area for combatants, a storage point, and had major industrial factories and workshops as well, and its air defenses consisted of five batteries of 7-cm and 8-cm (2.8 and 3.1 inch) anti-aircraft guns. Nagasaki was of great wartime importance because of its wide-ranging industrial activity, including the production of ordnance, warships, military equipment, and other war material. The city's air defenses consisted of four batteries of 7 cm (2.8 in) anti-aircraft guns and two searchlight batteries. An estimated 110,000 people were killed in the atomic bombings, including 20,000 Japanese combatants and 20,000 Korean slave laborers in Hiroshima and 23,145–28,113 Japanese factory workers, 2,000 Korean slave laborers, and 150 Japanese combatants in Nagasaki.

On 30 June 2007, Japan's defense minister Fumio Kyūma said the dropping of atomic bombs on Japan by the United States during World War II was an inevitable way to end the war. Kyūma said: "I now have come to accept in my mind that in order to end the war, it could not be helped (shikata ga nai) that an atomic bomb was dropped on Nagasaki and that countless numbers of people suffered great tragedy." Kyūma, who is from Nagasaki, said the bombing caused great suffering in the city, but he does not resent the U.S. because it prevented the Soviet Union from entering the war with Japan. Kyūma's comments were similar to those made by Emperor Hirohito when, in his first ever press conference given in Tokyo in 1975, he was asked what he thought of the bombing of Hiroshima, and answered: "It's very regrettable that nuclear bombs were dropped and I feel sorry for the citizens of Hiroshima but it couldn't be helped (shikata ga nai) because that happened in wartime."

In early July 1945, on his way to Potsdam, Truman had re-examined the decision to use the bomb. In the end, he made the decision to drop the atomic bombs on strategic cities. His stated intention in ordering the bombings was to save American lives, to bring about a quick resolution of the war by inflicting destruction, and instilling fear of further destruction, sufficient to cause Japan to surrender. In his speech to the Japanese people presenting his reasons for surrender on August 15, the Emperor referred specifically to the atomic bombs, stating if they continued to fight it would not only result in "an ultimate collapse and obliteration of the Japanese nation, but also it would lead to the total extinction of human civilization".

Commenting on the use of the atomic bomb, then-U.S. Secretary of War Henry L. Stimson stated, "The atomic bomb was more than a weapon of terrible destruction; it was a psychological weapon."

In 1959, Mitsuo Fuchida, the pilot who led the first wave in the surprise attack on Pearl Harbor, met with General Paul Tibbets, who piloted the '' Enola Gay'' that dropped the atomic bomb on Hiroshima, and told him that:

Former U.S. Secretary of Defense Robert McNamara, who worked as a USAAF statistic bomber analyst under LeMay's command at the time, stated in the documentary '' The Fog of War'' that brute force was sometimes necessary to quickly end the war:

Japan's leaders refused to surrender

Some historians see ancient Japanese warrior traditions as a major factor in the resistance in the Japanese military to the idea of surrender. According to one Air Force account,

Japanese militarism was aggravated by the Great Depression, and had resulted in countless assassinations of reformers attempting to check military power, among them Takahashi Korekiyo, Saitō Makoto, and Inukai Tsuyoshi. This created an environment in which opposition to war was a much riskier endeavor.

According to historian Richard B. Frank,

The United States Department of Energy's history of the Manhattan Project lends some credence to these claims, saying that military leaders in Japan

While some members of the civilian leadership did use covert diplomatic channels to attempt peace negotiation, they could not negotiate surrender or even a cease-fire. Japan could legally enter into a peace agreement only with the unanimous support of the Japanese cabinet, and in the summer of 1945, the Japanese Supreme War Council, consisting of representatives of the Army, the Navy, and the civilian government, could not reach a consensus on how to proceed.

A political stalemate developed between the military and civilian leaders of Japan, the military increasingly determined to fight despite all costs and odds and the civilian leadership seeking a way to negotiate an end to the war. Further complicating the decision was the fact no cabinet could exist without the representative of the Imperial Japanese Army. This meant the Army or Navy could veto any decision by having its Minister resign, thus making them the most powerful posts on the SWC. In early August 1945, the cabinet was equally split between those who advocated an end to the war on one condition, the preservation of the ''kokutai'', and those who insisted on three other conditions:
# Leave disarmament and demobilization to Imperial General Headquarters
# No occupation of the Japanese Home Islands, Korea, or Formosa
# Delegation to the Japanese government of the punishment of war criminals

The "hawks" consisted of General Korechika Anami, General Yoshijirō Umezu, and Admiral Soemu Toyoda and were led by Anami. The "doves" consisted of Prime Minister Kantarō Suzuki, Naval Minister Mitsumasa Yonai, and Minister of Foreign Affairs Shigenori Tōgō and were led by Togo. Under special permission of Hirohito, the president of the Privy council, Hiranuma Kiichirō, was also a member of the imperial conference. For him, the preservation of the ''kokutai'' implied not only the Imperial institution but also the Emperor's reign.

Japan had an example of unconditional surrender in the German Instrument of Surrender. On 26 July, Truman and other Allied leaders—except the Soviet Union—issued the Potsdam Declaration outlining terms of surrender for Japan. The declaration stated, "The alternative for Japan is prompt and utter destruction." It was not accepted, though there is debate on Japan's intentions. The Emperor, who was waiting for a Soviet reply to Japanese peace feelers, made no move to change the government position. In the PBS documentary "Victory in the Pacific" (2005), broadcast in the ''American Experience'' series, historian Donald Miller argues, in the days after the declaration, the Emperor seemed more concerned with moving the Imperial Regalia of Japan to a secure location than with "the destruction of his country". This comment is based on declarations made by the Emperor to Kōichi Kido on 25 and 31 July 1945, when he ordered the Lord Keeper of the Privy Seal of Japan to protect "at all cost" the Imperial Regalia.

It has sometimes been argued Japan would have surrendered if simply guaranteed the Emperor would be allowed to continue as formal head of state. However, Japanese diplomatic messages regarding a possible Soviet mediation—intercepted through Magic, and made available to Allied leaders—have been interpreted by some historians to mean, "the dominant militarists insisted on preservation of the old militaristic order in Japan, the one in which they ruled." On 18 and 20 July 1945, Ambassador Sato cabled to Foreign Minister Togo, strongly advocating that Japan accept an unconditional surrender provided that the U.S. preserved the imperial house (keeping the emperor). On 21 July, in response, Togo rejected the advice, saying that Japan would not accept an unconditional surrender under any circumstance. Togo then said that, "Although it is apparent that there will be more casualties on both sides in case the war is prolonged, we will stand as united against the enemy if the enemy forcibly demands our unconditional surrender." They also faced potential death sentences in trials for Japanese war crimes if they surrendered. This was also what occurred in the International Military Tribunal for the Far East and other tribunals. Further diplomatic cables suggest the Japanese ambassador in Moscow thought the Foreign Ministry in Tokyo had an unrealistic view of events.

History professor Robert James Maddox wrote:

Maddox also wrote, "Even after both bombs had fallen and Russia entered the war, Japanese militants insisted on such lenient peace terms that moderates knew there was no sense even transmitting them to the United States. Hirohito had to intervene personally on two occasions during the next few days to induce hardliners to abandon their conditions." "That they would have conceded defeat months earlier, before such calamities struck, is far-fetched to say the least."

Even after the triple shock of the Soviet intervention and two atomic bombs, the Japanese cabinet was still deadlocked, incapable of deciding upon a course of action due to the power of the Army and Navy factions in cabinet who were unwilling to even consider surrender. Following the personal intervention of the emperor to break the deadlock in favour of surrender, there were no fewer than three separate coup attempts by senior Japanese officers to try to prevent the surrender and take the Emperor into 'protective custody'. Once these coup attempts had failed, senior leaders of the air force and Navy ordered bombing and ''kamikaze'' raids on the U.S. fleet (in which some Japanese generals personally participated) to try to derail any possibility of peace. It is clear from these accounts that while many in the civilian government knew the war could not be won, the power of the military in the Japanese government kept surrender from even being considered as a real option prior to the two atomic bombs.

Another argument is that it was the Soviet declaration of war in the days between the bombings that caused the surrender. After the war, Admiral Soemu Toyoda said, "I believe the Russian participation in the war against Japan rather than the atom bombs did more to hasten the surrender." Prime Minister Suzuki also declared that the entry of the USSR into the war made "the continuance of the war impossible". Upon hearing news of the event from Foreign Minister Togo, Suzuki immediately said, "Let us end the war", and agreed to finally convene an emergency meeting of the Supreme Council with that aim. The official British history, ''The War Against Japan'', also writes the Soviet declaration of war "brought home to all members of the Supreme Council the realization that the last hope of a negotiated peace had gone and there was no alternative but to accept the Allied terms sooner or later". However, others have argued the Soviet declaration of war would not have come as a large shock to the Japanese leadership unlike the atomic bombings as they were aware of a Soviet military buildup in the Far East for months anticipating an eventual attack at a later date.

The "one condition" faction, led by Togo, seized on the bombing as decisive justification of surrender. Kōichi Kido, one of Emperor Hirohito's closest advisers, stated, "We of the peace party were assisted by the atomic bomb in our endeavor to end the war." Hisatsune Sakomizu, the chief Cabinet secretary in 1945, called the bombing "a golden opportunity given by heaven for Japan to end the war".

Japanese nuclear weapon program

During the war, and 1945 in particular, due to state secrecy, very little was known outside Japan about the slow progress of the Japanese nuclear weapon program. The US knew that Japan had requested materials from their German allies, and of unprocessed uranium oxide was dispatched to Japan in April 1945 aboard the submarine ''U-234'', which however surrendered to US forces in the Atlantic following Germany's surrender. The uranium oxide was reportedly labeled as "U-235", which may have been a mislabeling of the submarine's name; its exact characteristics remain unknown. Some sources believe that it was not weapons-grade material and was intended for use as a catalyst in the production of synthetic methanol to be used for aviation fuel...

If post-war analysis had found that Japanese nuclear weapons development was near completion, this discovery might have served in a revisionist sense to justify the atomic attack on Japan. However, it is known that the poorly coordinated Japanese project was considerably behind the US developments in 1945,Dees, pp. 20–21 and also behind the unsuccessful German nuclear energy project of WWII.

A review in 1986 of the fringe hypothesis that Japan had ''already'' created a nuclear weapon, by Department of Energy employee Roger M. Anders, appeared in the journal ''Military Affairs'':

Soviet Interference

Post-World War 2 Japan, under the circumstance that the United States did not drop the two atomic weapons on Japan, could have seen a state of existence comparable to that of Korea and Germany, in the years of Russian/communist occupation on one side and Western occupation on the other. This would not be completely unthinkable due to the Proposed Soviet invasion of Hokkaido, a planned invasion of the northernmost island of the Japanese home islands, which was supposed to start two months before the American Invasion of Kyushu (the southernmost island). Had the Soviets actually commenced the aforementioned invasion and, for that matter, succeeded, they would gain a foothold in an island of immense strategic relevance. In that respect, the United States' (as well as their allies') plan, known as Operation Downfall, may have become a gambit in a situation that could be dangerous or perhaps deadly for the interests of the United States, her allies, and maybe even the world.

While valid projections or viable predictions for such a situation are scarce, a detailed analysis of similar, empirically observed situations provides legitimate reasons to consider Soviet interference a valid concern. In many cases under the criteria that Soviet/communist influence/occupation is observed on part of the country or region and Western influence seen on another, conflict erupted. A few examples of this would include: The Korean War, where a Soviet-backed North Korea invaded the pro-Western South Korea, and ultimately resulted in a multinational war with a UN Coalition, primarily consisting of American forces, versus a joint DRPK-Chinese Communist Party force; The Berlin Blockade, where the USSR sought to starve the pro-Western West Berlin into submission, but ultimately failed due to the Berlin Airlift; The Vietnam War, a Cold War proxy-conflict between the U.S. and USSR, which pitted the pro-Communist North Vietnam against the American-backed South, and so on so forth. In fact, the vacuum left after Japan's surrender in contested areas of China became a shady duel between communism and democracy, as Eugene Sledge writes in the book ''The Cold War: A Military History'': "In northern China at this time were many different armed groups: Japanese, Japanese-trained and -equipped Chinese puppet-government soldiers, Chinese Communists, Chinese Nationalists, Chinese bandits, and U.S. Marines... In Lang Fang and many other areas, even the surrendered Japanese were allowed to retain their arms, under U.S. supervision, in order to help fight the Communists".

Other

Oppenheimer and Bohr, who played central roles in the development of the weapons, along with many others working at Los Alamos, had ethical reservations about helping develop the weapon but ultimately found developing the weapon for its use on Japan to be justified. Robert Willson, referring to a conversation with Oppenheimer in late 1944, said "We did have a pretty intense discussion of why it was that we were continuing to make a bomb after the war had been irtuallywon." The book American Prometheus, notes that while "no official records were kept of these sensitive discussions" and only post hoc accounts from the scientists there are available, it is contended that "Oppenheimer argued with his usual eloquence that, although they were all destined to live in perpetual fear, the bomb might also end all war...Such a hope, echoing Bohr’s words, was persuasive to many of the assembled scientists."

Truman felt that the effects of Japan witnessing a failed test would be too great of a risk to arrange such a demonstration.

It emerged after the war that Japanese biological warfare unit had a plan to attack the United States with biological weapons in September, though not approved by higher authorities before the end of the war.

Opposition

Militarily unnecessary

Assistant Secretary Bard was convinced that a standard bombardment and naval blockade would be enough to force Japan into surrendering. Even more, he had seen signs for weeks that the Japanese were actually already looking for a way out of the war. His idea was for the United States to tell the Japanese about the bomb, the impending Soviet entry into the war, and the fair treatment that citizens and the Emperor would receive at the coming Big Three conference. Before the bombing occurred, Bard pleaded with Truman to neither drop the bombs (at least not without warning the population first) nor to invade the entire country, proposing to stop the bloodshed.

The 1946 United States Strategic Bombing Survey in Japan, whose members included Paul Nitze, concluded the atomic bombs had been unnecessary to win the war. They said:

This conclusion assumed conventional firebombing would have continued, with ever-increasing numbers of B-29s, and a greater level of destruction to Japan's cities and population. One of Nitze's most influential sources was Prince Fumimaro Konoe, who responded to a question asking whether Japan would have surrendered if the atomic bombs had not been dropped by saying resistance would have continued through November or December 1945.

Historians such as Bernstein, Hasegawa, and Newman have criticized Nitze for drawing a conclusion they say went far beyond what the available evidence warranted, in order to promote the reputation of the Air Force at the expense of the Army and Navy.

Dwight D. Eisenhower wrote in his memoir ''The White House Years'':

Other U.S. military officers who disagreed with the necessity of the bombings include General of the Army Douglas MacArthur, Fleet Admiral William D. Leahy (the Chief of Staff to the President), Brigadier General Carter Clarke (the military intelligence officer who prepared intercepted Japanese cables for U.S. officials), Fleet Admiral Chester W. Nimitz (Commander in Chief of the Pacific Fleet), Fleet Admiral William Halsey Jr. (Commander of the US Third Fleet), and even the man in charge of all strategic air operations against the Japanese home islands, then-Major General Curtis LeMay:

Stephen Peter Rosen of Harvard believes that a submarine blockade would have been sufficient to force Japan to surrender.

Historian Tsuyoshi Hasegawa wrote the atomic bombings themselves were not the principal reason for Japan's capitulation.. Instead, he contends, it was the Soviet entry in the war on 8 August, allowed by the Potsdam Declaration signed by the other Allies. The fact the Soviet Union did not sign this declaration gave Japan reason to believe the Soviets could be kept out of the war. As late as 25 July, the day before the declaration was issued, Japan had asked for a diplomatic envoy led by Konoe to come to Moscow hoping to mediate peace in the Pacific. Konoe was supposed to bring a letter from the Emperor stating:

Hasegawa's view is, when the Soviet Union declared war on 8 August, it crushed all hope in Japan's leading circles that the Soviets could be kept out of the war and also that reinforcements from Asia to the Japanese islands would be possible for the expected invasion. Hasegawa wrote:

Ward Wilson wrote that "after Nagasaki was bombed only four major cities remained which could readily have been hit with atomic weapons", and that the Japanese Supreme Council did not bother to convene after the atomic bombings because they were barely more destructive than previous bombings. He wrote that instead, the Soviet declaration of war and invasion of Manchuria and South Sakhalin removed Japan's last diplomatic and military options for negotiating a ''conditional'' surrender, and this is what prompted Japan's surrender. He wrote that attributing Japan's surrender to a "miracle weapon", instead of the start of the Soviet invasion, saved face for Japan and enhanced the United States' world standing.

Bombings as war crimes

A number of notable individuals and organizations have criticized the bombings, many of them characterizing them as war crimes, crimes against humanity, and/or state terrorism. Early critics of the bombings were Albert Einstein, Eugene Wigner and Leó Szilárd, who had together spurred the first bomb research in 1939 with a jointly written letter to President Roosevelt.

Szilárd, who had gone on to play a major role in the Manhattan Project, argued:

A number of scientists who worked on the bomb were against its use. Led by Dr. James Franck, seven scientists submitted a report to the Interim Committee (which advised the President) in May 1945, saying:

Mark Selden writes, "Perhaps the most trenchant contemporary critique of the American moral position on the bomb and the scales of justice in the war was voiced by the Indian jurist Radhabinod Pal, a dissenting voice at the Tokyo War Crimes Tribunal, who balked at accepting the uniqueness of Japanese war crimes. Recalling Kaiser Wilhelm II's account of his duty to bring World War I to a swift end—"everything must be put to fire and sword; men, women and children and old men must be slaughtered and not a tree or house be left standing." Pal observed:

Selden mentions another critique of the nuclear bombing, which he says the U.S. government effectively suppressed for twenty-five years, as worth mention. On 11 August 1945, the Japanese government filed an official protest over the atomic bombing to the U.S. State Department through the Swiss Legation in Tokyo, observing:

Selden concludes, "the Japanese protest correctly pointed to U.S. violations of internationally accepted principles of war with respect to the wholesale destruction of populations".

In 1963, the bombings were the subject of a judicial review in ''Ryuichi Shimoda et al. v. The State'' in Japan. On the 22nd anniversary of the attack on Pearl Harbor, the District Court of Tokyo declined to rule on the legality of nuclear weapons in general, but found, "the attacks upon Hiroshima and Nagasaki caused such severe and indiscriminate suffering that they did violate the most basic legal principles governing the conduct of war."

In the opinion of the court, the act of dropping an atomic bomb on cities was at the time governed by international law found in the Hague Regulations on Land Warfare of 1907 and the Hague Draft Rules of Air Warfare of 1922–1923 and was therefore illegal.

In the documentary ''The Fog of War'', former U.S. Secretary of Defense Robert McNamara recalls General Curtis LeMay, who relayed the Presidential order to drop nuclear bombs on Japan, said:

As the first combat use of nuclear weapons, the bombings of Hiroshima and Nagasaki represent to some the crossing of a crucial barrier. Peter Kuznick, director of the Nuclear Studies Institute at American University, wrote of President Truman: "He knew he was beginning the process of annihilation of the species."
Kuznick said the atomic bombing of Japan "was not just a war crime; it was a crime against humanity."

Takashi Hiraoka, mayor of Hiroshima, upholding nuclear disarmament, said in a hearing to The Hague International Court of Justice (ICJ): "It is clear that the use of nuclear weapons, which cause indiscriminate mass murder that leaves ffects onsurvivors for decades, is a violation of international law".November 1995 Public Sitting, in the Case of Legality of the Use by a State of Nuclear Weapons in Armed Conflicts
at La Hague International Court of Justice Iccho Itoh, the mayor of Nagasaki, declared in the same hearing:

Although bombings do not meet the definition of genocide, some consider the definition too strict, and argue the bombings do constitute genocide. For example, University of Chicago historian Bruce Cumings states there is a consensus among historians to Martin Sherwin's statement, " e Nagasaki bomb was gratuitous at best and genocidal at worst".

The scholar R. J. Rummel instead extends the definition of genocide to what he calls democide, and includes the major part of deaths from the atom bombings in these. His definition of democide includes not only genocide, but also an excessive killing of civilians in war, to the extent this is against the agreed rules for warfare; he argues the bombings of Hiroshima and Nagasaki were war crimes, and thus democide.
Rummel quotes among others an official protest from the US government in 1938 to Japan, for its bombing of Chinese cities: "The bombing of non-combatant populations violated international and humanitarian laws." He also considers excess deaths of civilians in conflagrations caused by conventional means, such as in Tokyo, as acts of democide.

In 1967, Noam Chomsky described the atomic bombings as "among the most unspeakable crimes in history". Chomsky pointed to the complicity of the American people in the bombings, referring to the bitter experiences they had undergone prior to the event as the cause for their acceptance of its legitimacy.

In 2007, a group of intellectuals in Hiroshima established an unofficial body called International Peoples' Tribunal on the Dropping of Atomic Bombs on Hiroshima and Nagasaki. On 16 July 2007, it delivered its verdict, stating:

About the legality and the morality of the action, the unofficial tribunal found:

State terrorism

Historical accounts indicate the decision to use the atomic bombs was made in order to provoke a surrender of Japan by use of an awe-inspiring power. These observations have caused Michael Walzer to state the incident was an act of "war terrorism: the effort to kill civilians in such large numbers that their government is forced to surrender. Hiroshima seems to me the classic case."
This type of claim eventually prompted historian Robert P. Newman, a supporter of the bombings, to say "there ''can'' be justified terror, as there can be just wars".

Certain scholars and historians have characterized the atomic bombings of Japan as a form of "state terrorism". This interpretation is based on a definition of terrorism as "the targeting of innocents to achieve a political goal". As Frances V. Harbour points out, the meeting of the Target Committee in Los Alamos on 10 and 11 May 1945 suggested targeting the large population centers of Kyoto or Hiroshima for a "psychological effect" and to make "the initial use sufficiently spectacular for the importance of the weapon to be internationally recognized".. As such, Professor Harbour suggests the goal was to create terror for political ends both in and beyond Japan. However, Burleigh Taylor Wilkins believes it stretches the meaning of "terrorism" to include wartime acts..

Historian Howard Zinn wrote that the bombings were terrorism. Zinn cites the sociologist Kai Erikson who said that the bombings could not be called "combat" because they targeted civilians. Just War theorist Michael Walzer said that while taking the lives of civilians can be justified under conditions of 'supreme emergency', the war situation at that time did not constitute such an emergency.

Tony Coady, Frances V. Harbour, and Jamal Nassar also view the targeting of civilians during the bombings as a form of terrorism. Nassar classifies the atomic bombings as terrorism in the same vein as the firebombing of Tokyo, the firebombing of Dresden, and the Holocaust..

Richard A. Falk, professor Emeritus of International Law and Practice at Princeton University has written in detail about Hiroshima and Nagasaki as instances of state terrorism. He said that "the explicit function of the attacks was to terrorize the population through mass slaughter and to confront its leaders with the prospect of national annihilation"..

Author Steven Poole said that the "people killed by terrorism" are not the targets of the intended terror effect. He said that the atomic bombings were "designed as an awful demonstration" aimed at Stalin and the government of Japan.

Alexander Werth, historian and BBC
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