Franklin Roosevelt signing declaration of war against Germany

A declaration of war is a formal act by which one

state State may refer to: Arts, entertainment, and media Literature * ''State Magazine'', a monthly magazine published by the U.S. Department of State * ''The State'' (newspaper), a daily newspaper in Columbia, South Carolina, United States * ''Our S ...

announces existing or impending

war War is an intense armed conflict between states, governments, societies, or paramilitary groups such as mercenaries, insurgents, and militias. It is generally characterized by extreme violence, destruction, and mortality, using regular o ...

activity against another. The declaration is a performative

speech act In the philosophy of language and linguistics, speech act is something expressed by an individual that not only presents information but performs an action as well. For example, the phrase "I would like the kimchi; could you please pass it to me?" ...

(or the signing of a document) by an authorized party of a national government, in order to create a state of war between two or more states. The legality of who is competent to declare war varies between nations and forms of government. In many nations, that power is given to the

head of state A head of state (or chief of state) is the public persona who officially embodies a state Foakes, pp. 110–11 " he head of statebeing an embodiment of the State itself or representatitve of its international persona." in its unity and l ...

sovereign ''Sovereign'' is a title which can be applied to the highest leader in various categories. The word is borrowed from Old French , which is ultimately derived from the Latin , meaning 'above'. The roles of a sovereign vary from monarch, ruler or ...

. In other cases, something short of a full declaration of war, such as a letter of marque or a

covert operation A covert operation is a military operation intended to conceal the identity of (or allow plausible deniability by) the party that instigated the operation. Covert operations should not be confused with clandestine operations, which are performe ...

, may authorise war-like acts by

privateer A privateer is a private person or ship that engages in maritime warfare under a commission of war. Since robbery under arms was a common aspect of seaborne trade, until the early 19th century all merchant ships carried arms. A sovereign or deleg ...

s or

mercenaries A mercenary, sometimes also known as a soldier of fortune or hired gun, is a private individual, particularly a soldier, that joins a military conflict for personal profit, is otherwise an outsider to the conflict, and is not a member of any o ...

. The official international protocol for declaring war was defined in the Hague Convention (III) of 1907 on the Opening of Hostilities. Since 1945, developments in international law such as the

United Nations Charter The Charter of the United Nations (UN) is the foundational treaty of the UN, an intergovernmental organization. It establishes the purposes, governing structure, and overall framework of the UN system, including its six principal organs: the ...

, which prohibits both the threat and the use of force in international conflicts, have made declarations of war largely obsolete in international relations, though such declarations may have relevance within the domestic law of the belligerents or of neutral nations. The UN Security Council, under powers granted in articles 24 and 25, and Chapter VII of the Charter, may authorize

collective action Collective action refers to action taken together by a group of people whose goal is to enhance their condition and achieve a common objective. It is a term that has formulations and theories in many areas of the social sciences including psych ...

to maintain or enforce international peace and security. Article 51 of the United Nations Charter also states that: "Nothing in the present Charter shall impair the inherent right to individual or collective self-defence if an armed attack occurs against a state." Few nations have formally declared war upon another since then. In addition to this, non-state or

terrorist Terrorism, in its broadest sense, is the use of criminal violence to provoke a state of terror or fear, mostly with the intention to achieve political or religious aims. The term is used in this regard primarily to refer to intentional violen ...

organizations may claim to or be described as "declaring war" when engaging in violent acts. These declarations may have no legal standing in themselves, but they may still act as a call to arms for supporters of these organizations.

History

The practice of declaring war has a long history. The ancient Sumerian

Epic of Gilgamesh The ''Epic of Gilgamesh'' () is an epic poetry, epic poem from ancient Mesopotamia, and is regarded as the earliest surviving notable literature and the second oldest religious text, after the Pyramid Texts. The literary history of Gilgamesh ...

gives an account of it, as does the

Old Testament The Old Testament (often abbreviated OT) is the first division of the Christian biblical canon, which is based primarily upon the 24 books of the Hebrew Bible or Tanakh, a collection of ancient religious Hebrew writings by the Israelites. The ...

. The

Roman Republic The Roman Republic ( la, Res publica Romana ) was a form of government of Rome and the era of the classical Roman civilization when it was run through public representation of the Roman people. Beginning with the overthrow of the Roman Kin ...

formalized the declaration of war by a special ceremony, the ritual of the

Fetials A fetial (; la, fētiālis , . la, fētiālēs, label=none) was a type of priest in ancient Rome. They formed a ''collegium'' devoted to Jupiter as the patron of good faith. The duties of the fetials included advising the Senate on foreign aff ...

, though the practice started to decline into the

Imperial Imperial is that which relates to an empire, emperor, or imperialism. Imperial or The Imperial may also refer to: Places United States * Imperial, California * Imperial, Missouri * Imperial, Nebraska * Imperial, Pennsylvania * Imperial, Texa ...

era. However, the practice of declaring war was not always strictly followed. In his study ''Hostilities without Declaration of War'' (1883), the British scholar

John Frederick Maurice Major-General Sir John Frederick Maurice (24 May 1841 – 12 January 1912) was a senior British Army officer, chiefly remembered for his military writings. Family and early life Maurice was born in Southwark, London in 1841, the eldest son of R ...

showed that between 1700 and 1870 war was declared in only 10 cases, while in another 107 cases war was waged without such declaration (these figures include only wars waged in Europe and between European states and the United States, not including colonial wars in Africa and Asia). In modern

public international law International law (also known as public international law and the law of nations) is the set of rules, norms, and standards generally recognized as binding between states. It establishes normative guidelines and a common conceptual framework for ...

, a declaration of war entails the recognition between countries of a state of hostilities between these countries, and such declaration has acted to regulate the conduct between the military engagements between the forces of the respective countries. The primary multilateral

treaties A treaty is a formal, legally binding written agreement between actors in international law. It is usually made by and between sovereign states, but can include international organizations, individuals, business entities, and other legal pers ...

governing such declarations are the Hague Conventions. The

League of Nations The League of Nations (french: link=no, Société des Nations ) was the first worldwide intergovernmental organisation whose principal mission was to maintain world peace. It was founded on 10 January 1920 by the Paris Peace Conference that ...

, formed in 1919 in the wake of the

First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

, and the

General Treaty for the Renunciation of War A general officer is an officer of high rank in the armies, and in some nations' air forces, space forces, and marines or naval infantry. In some usages the term "general officer" refers to a rank above colonel."general, adj. and n.". OED O ...

of 1928 signed in

Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. S ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

, demonstrated that world powers were seriously seeking a means to prevent the carnage of another world war. Nevertheless, these powers were unable to stop the outbreak of the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

, so the

United Nations The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and international security, security, develop friendly relations among nations, achieve international cooperation, and be ...

was established following that war in a renewed attempt to prevent international aggression through declarations of war.

Denigration of formal declarations of war before WWII

In classical times,

Thucydides Thucydides (; grc, , }; BC) was an Athenian historian and general. His ''History of the Peloponnesian War'' recounts the fifth-century BC war between Sparta and Athens until the year 411 BC. Thucydides has been dubbed the father of "scientifi ...

condemned the

Thebans Thebes (; ell, Θήβα, ''Thíva'' ; grc, Θῆβαι, ''Thêbai'' .) is a city in Boeotia, Central Greece. It played an important role in Greek myths, as the site of the stories of Cadmus, Oedipus, Dionysus, Heracles and others. Archaeolog ...

, allies of

Sparta Sparta ( Doric Greek: Σπάρτα, ''Spártā''; Attic Greek: Σπάρτη, ''Spártē'') was a prominent city-state in Laconia, in ancient Greece. In antiquity, the city-state was known as Lacedaemon (, ), while the name Sparta referre ...

, for launching a surprise attack without a declaration of war against

Plataea Plataea or Plataia (; grc, Πλάταια), also Plataeae or Plataiai (; grc, Πλαταιαί), was an ancient city, located in Greece in southeastern Boeotia, south of Thebes.Mish, Frederick C., Editor in Chief. “Plataea.” '' Webst ...

Athens Athens ( ; el, Αθήνα, Athína ; grc, Ἀθῆναι, Athênai (pl.) ) is both the capital and largest city of Greece. With a population close to four million, it is also the seventh largest city in the European Union. Athens dominates ...

' ally – an event that began the

Peloponnesian War The Peloponnesian War (431–404 BC) was an ancient Greek war fought between Athens and Sparta and their respective allies for the hegemony of the Greek world. The war remained undecided for a long time until the decisive intervention of th ...

. The utility of formal declarations of war has always been questioned, either as sentimental remnants of a long-gone age of

chivalry Chivalry, or the chivalric code, is an informal and varying code of conduct developed in Europe between 1170 and 1220. It was associated with the medieval Christianity, Christian institution of knighthood; knights' and gentlemen's behaviours we ...

or as imprudent warnings to the enemy. For example, writing in 1737,

Cornelius van Bynkershoek Cornelis van Bijnkershoek (a.k.a. ''Cornelius van Bynkershoek'') (29 May 1673, in Middelburg – 16 April 1743, in The Hague) was a Dutch jurist and legal theorist who was educated at the University of Franeker. After two years study, he began to ...

judged that "nations and princes endowed with some pride are not generally willing to wage war without a previous declaration, for they wish by an open attack to render victory more honourable and glorious." Writing in 1880,

William Edward Hall William Edward Hall (22 August 183530 November 1894) was an English lawyer and mountaineer who published some influential works on international law. Early life Hall was the only child of William Hall, a doctor and descendant of a junior bran ...

judged that "any sort of previous declaration therefore is an empty formality unless the enemy must be given time and opportunity to put himself in a state of defence, and it is needless to say that no one asserts such a quixotism to be obligatory."

Formal declarations of war during World War I

Formal declarations of war during World War II

Declared wars since 1945

Declarations of war, while uncommon in the traditional sense, have mainly been limited to the conflict areas of the

Western Asia Western Asia, West Asia, or Southwest Asia, is the westernmost subregion of the larger geographical region of Asia, as defined by some academics, UN bodies and other institutions. It is almost entirely a part of the Middle East, and includes Ana ...

and

East Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historical ...

since 1945. Additionally, some small states have unilaterally declared war on major world powers such as the United States, United Kingdom, or Russia when faced with a hostile invasion and/or occupation. The following is a list of declarations of war (or the existence of war) by one sovereign state against another since the end of World War II in 1945. Only declarations that occurred in the context of a direct military conflict are included.

Russo-Ukrainian War

No formal declaration of war has been issued in the ongoing

Russo-Ukrainian War The Russo-Ukrainian War; uk, російсько-українська війна, rosiisko-ukrainska viina. has been ongoing between Russia (alongside Russian separatist forces in Donbas, Russian separatists in Ukraine) and Ukraine since Feb ...

. When Russia's president

Vladimir Putin Vladimir Vladimirovich Putin; (born 7 October 1952) is a Russian politician and former intelligence officer who holds the office of president of Russia. Putin has served continuously as president or prime minister since 1999: as prime min ...

announced the

2022 Russian invasion of Ukraine On 24 February 2022, in a major escalation of the Russo-Ukrainian War, which began in 2014. The invasion has resulted in tens of thousands of deaths on both sides. It has caused Europe's largest refugee crisis since World War II. An ...

, he claimed to commence a "special military operation", side-stepping a formal declaration of war. The statement was, however, regarded as a declaration of war by the Ukrainian government and reported as such by numerous international news sources. While the Ukrainian parliament refers to Russia as a "terrorist state" in regards to its military actions in Ukraine, it has not issued a formal declaration of war on its behalf, therefore establishing the de facto state of war.

Procedures

In the first Hague Convention of 1899, the signatory states agreed that at least one other nation be used to mediate disputes between states before engaging in hostilities: ;1899

Title II, Article 2

In case of serious disagreement or conflict, before an appeal to arms, the signatory Powers agree to have recourse, as far as circumstances allow, to the good offices or mediation of one or more friendly Powers. ;1907 The Hague Convention (III) of 1907 called " Convention Relative to the Opening of Hostilities" gives the international actions a country should perform when opening hostilities. The first two Articles say:

Article 1

::The Contracting Powers recognize that hostilities between themselves must not commence without previous and explicit warning, in the form either of a reasoned declaration of war or of an ultimatum with conditional declaration of war.

Article 2

::The existence of a state of war must be notified to the neutral Powers without delay, and shall not take effect in regard to them until after the receipt of a notification, which may, however, be given by telegraph. Neutral Powers, nevertheless, cannot rely on the absence of notification if it is clearly established that they were in fact aware of the existence of a state of war.

United Nations and war

In an effort to force nations to resolve issues without warfare, framers of the United Nations Charter attempted to commit member nations to using warfare only under limited circumstances, particularly for defensive purposes. The UN became a

combatant Combatant is the legal status of an individual who has the right to engage in hostilities during an armed conflict. The legal definition of "combatant" is found at article 43(2) of Additional Protocol I (AP1) to the Geneva Conventions of 1949. It ...

itself after

North Korea North Korea, officially the Democratic People's Republic of Korea (DPRK), is a country in East Asia. It constitutes the northern half of the Korea, Korean Peninsula and shares borders with China and Russia to the north, at the Yalu River, Y ...

invaded

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...

on 25 June 1950, which begun the

Korean War , date = {{Ubl, 25 June 1950 – 27 July 1953 (''de facto'')({{Age in years, months, weeks and days, month1=6, day1=25, year1=1950, month2=7, day2=27, year2=1953), 25 June 1950 – present (''de jure'')({{Age in years, months, weeks a ...

. The UN Security Council condemned the North Korean action by a 9–0 resolution (with the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...

absent) and called upon its member nations to come to the aid of South Korea. The United States and 15 other nations formed a "UN force" to pursue this action. In a

press conference A press conference or news conference is a media event in which notable individuals or organizations invite journalists to hear them speak and ask questions. Press conferences are often held by politicians, corporations, non-governmental organ ...

on 29 June 1950, US President

Harry S. Truman Harry S. Truman (May 8, 1884December 26, 1972) was the 33rd president of the United States, serving from 1945 to 1953. A leader of the Democratic Party, he previously served as the 34th vice president from January to April 1945 under Franklin ...

characterized these hostilities as not being a "war" but a "police action". The United Nations has issued Security Council Resolutions that declared some wars to be legal actions under international law, most notably Resolution

678 __NOTOC__ Year 678 (Roman numerals, DCLXXVIII) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. The denomination 678 for this year has been used since the early medieval period, when the Anno Do ...

, authorizing the 1991

Gulf War The Gulf War was a 1990–1991 armed campaign waged by a 35-country military coalition in response to the Iraqi invasion of Kuwait. Spearheaded by the United States, the coalition's efforts against Iraq were carried out in two key phases: ...

which was triggered by

Iraq Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq ...

's invasion of

Kuwait Kuwait (; ar, الكويت ', or ), officially the State of Kuwait ( ar, دولة الكويت '), is a country in Western Asia. It is situated in the northern edge of Eastern Arabia at the tip of the Persian Gulf, bordering Iraq to the nort ...

. UN Resolutions authorise the use of "force" or "all necessary means".

Legality

The legality of who is competent to declare war varies between nations and forms of government. In many nations, that power is given to the