Operation Greif was a special operation commanded by Waffen-SS commando Otto Skorzeny during the Battle of the Bulge in World War II. The operation was the brainchild of Adolf Hitler, and its purpose was to capture one or more of the bridges over the Meuse river before they could be destroyed. German soldiers, wearing captured British and U.S. Army uniforms and using captured Allied vehicles, were to cause confusion in the rear of the Allied lines. A lack of vehicles, uniforms and equipment limited the operation and it never achieved its original aim of securing the Meuse bridges. Skorzeny's post-war trial set a precedent clarifying article 4 of the Geneva Convention: as the German soldiers removed the Allied uniforms before engaging in combat, they were not to be considered francs-tireurs.

Otto Johann Anton Skorzeny was an Austrian-born German SS-Obersturmbannführer in the Waffen-SS during World War II. During the war, he was involved in a number of operations, including the removal from power of Hungarian Regent Miklós Horthy and the Gran Sasso raid which rescued Benito Mussolini from captivity. Skorzeny led Operation Greif in which German soldiers infiltrated Allied lines wearing their enemies' uniforms. As a result, he was charged in 1947 at the Dachau Military Tribunal with breaching the 1907 Hague Convention, but was acquitted.