Declarations of war during World War II

This is a timeline of declarations of war during World War II.

A declaration of war is a formal act by which one nation goes to war against another. The declaration is usually the act of delivering a performative speech or the presentation of a signed document by an authorized party of a national government in order to create a state of war between two or more sovereign states. The official international protocol for declaring war was defined in The Hague Peace Conference of 1907 (or Hague II).''On the Opening of Hostilities''
1907; Yale Law School Library; retrieved March 2014. For the diplomatic maneuvering behind these events, which led to hostilities between nations during World War II, see Diplomatic history of World War II.

List of war declarations

Below is a table showing the outbreak of wars between nations which occurred during World War II. Indicated are the dates (during the immediate build-up to, or during the course of, World War II), from which a ''de facto'' state of war existed between nations. The table shows both the "Initiator Nation(s)" and the nation at which the aggression was aimed, or "Targeted Nation(s)". Events listed include those in which there were simple diplomatic breaking of relations that did not involve any physical attack, as well as those involving overt declarations or acts of aggression. In rare cases, war between two nations occurred twice, with an intermittent period of peace. The list here does not include peace treaties or periods of any armistice.

Key to type (fourth column):

A = Attack without prior, formal declaration of war;
C = Declaration and/or attack without standard, formal procedure, sometimes preceded by a ''casus belli'' thus ''fait accompli'';
U = State of war arrived at through use of ultimatum;
W = Formal declaration of war made.

Gallery

File:Bundesarchiv Bild 183-B0527-0001-293, Warschau, Empfang Goebbels bei Marschall Pilsudski.jpg, German ambassador, Hans-Adolf von Moltke, Polish leader Józef Piłsudski, German propaganda minister Joseph Goebbels and Józef Beck, Polish Foreign minister meeting in Warsaw on June 15, 1934, five months after signing the Polish-German Non-Aggression Pact.
File:MunichAgreement.jpg, British Prime Minister Neville Chamberlain, landing at Heston aerodrome on 30 September 1938 after his meeting with Hitler at Munich. In his hand he holds the peace agreement between Britain and Germany.
File:Armia Czerwona,Wehrmacht 23.09.1939 wspólna parada.jpg, Common parade of German Wehrmacht and Soviet Red Army on September 23, 1939 in Brest, Eastern Poland at the end of the Poland Campaign. In the center is Major General Heinz Guderian; and on the right is Brigadier General Semyon Krivoshein.
File:Moscow negotiations paaskivi yrjokoskinen nykopp paasonen 1939.png, alt=A group of four men wearing hats and a train behind., Counsellor of state J.K. Paasikivi and his team arriving from Moscow for the first round of negotiations on 16 October 1939. From left, minister Aarno Yrjö-Koskinen, J.K. Paasikivi, chief of staff Johan Nykopp and colonel Aladár Paasonen.
File:German paratroopers jumping From Ju 52s over Crete.jpg, German paratroopers taking the Greek island of Crete, May 1941.
File:Attack on Pearl Harbor Japanese planes view.jpg, Photograph from a Japanese plane of Battleship Row at the beginning of the surprise Attack on Pearl Harbor. The explosion in the center is a torpedo strike on the USS ''Oklahoma''. Two attacking Japanese planes can be seen: one over the USS ''Neosho'' and one over the Naval Yard.

See also

* Diplomatic history of World War II
*Allies of World War II
*Axis powers: German Instrument of Surrender and Surrender of Japan

Notes

References

{{World War II

declaration
Chronology of World War II
Modern history timelines