Instances of Use of United States Armed Forces Abroad, 1798-2016 [October 7, 2016] [open pdf - 888KB]
"This report lists hundreds of instances in which the United States has used its Armed Forces abroad in situations of military conflict or potential conflict or for other than normal peacetime purposes. It was compiled in part from various older lists and is intended primarily to provide a rough survey of past U.S. military ventures abroad, without reference to the magnitude of the given instance noted. The listing often contains references, especially from 1980 forward, to continuing military deployments, especially U.S. military participation in multinational operations associated with NATO or the United Nations. Most of these post-1980 instances are summaries based on presidential reports to Congress related to the War Powers Resolution. A comprehensive commentary regarding any of the instances listed is not undertaken here. The instances differ greatly in number of forces, purpose, extent of hostilities, and legal authorization. Eleven times in its history, the United States has formally declared war against foreign nations. [...] The majority of the instances listed prior to World War II were brief Marine Corps or Navy actions to protect U.S. citizens or promote U.S. interests. A number were engagements against pirates or bandits. Covert operations, disaster relief, and routine alliance stationing and training exercises are not included here, nor are the Civil and Revolutionary Wars and the continual use of U.S. military units in the exploration, settlement, and pacification of the western part of the United States."
CRS Report for Congress, R42738
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html