A police action in military/security studies and international relations, is a military action undertaken without a formal declaration of war, often localized in scope.

Since the Second World War, numerous police actions have taken place under the auspices of the major-power nations; indeed, a declared war is an increasing rarity.

The term is frequently used in reference to certain 20th-century historical events: the military actions of the Netherland, Britain, and other allies during the Indonesian National Revolution (1945-1949), as well as the Malayan Emergency (1948-1960).

The United States has launched all of its major armed conflicts since World war 2 as police actions. In these events, Congress had not made a formal declaration of war, yet the President, as the commander-in-chief, is authorized to send in the armed forces when s/he deems necessary. Nonetheless, some Congressional control is typically applied. Both the Korean War and the Vietnam, strictly speaking, are not declared wars but police actions.

Related topics

• Posse comitatus
• Korean War
• Gulf of Tonkin Resolution
• War Powers Resolution
• Declaration of war by the United States