Undeclared war
An undeclared war is a military conflict between two or more nations without either side issuing a formal declaration of war. The term is sometimes used to include any disagreement or conflict fought about without an official declaration. Since the United Nations police action in Korea,[1] some governments have pursued disciplinary actions and limited warfare by characterizing them as something else such as a military action or armed response.
This article is about the type of military conflict. For the 1990 film, see Undeclared War. For the 2022 television series, see The Undeclared War.Under customary international law, it is not necessary to declare war - simply beginning hostilities is sufficient to make belligerent intentions clear.[2]
Russia[edit]
No formal declaration of war has been issued in the ongoing Russo-Ukrainian War. When Russia's president Vladimir Putin announced the Russian invasion of Ukraine in 2022, he announced the start of a "Special military operation", side-stepping a formal declaration of war.[7]
United Kingdom[edit]
The Falklands War between Argentina and the United Kingdom (April - June 1982) was never formally declared as a war.[8]