Declarations of war during World War II

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.

[1] For the diplomatic maneuvering behind these events, which led to hostilities between nations during World War II, see Diplomatic history of World War II.

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.