Wartime collaboration

Wartime collaboration is cooperation with the enemy against one's country of citizenship in wartime.^[1] As historian Gerhard Hirschfeld says, it "is as old as war and the occupation of foreign territory".^[2]

The term collaborator dates to the 19th century and was used in France during the Napoleonic Wars. The meaning shifted during World War 2 to designate traitorous collaboration with the enemy. The related term collaborationism is used by historians who restrict the term to a subset of ideological collaborators in Vichy France who actively promoted German victory.