During the Second World War, Operation Clipper was an Allied offensive by the British XXX Corps (which included the American 84th Infantry Division) to reduce the Geilenkirchen salient in mid-November 1944. Clipper was the preliminary to a wider Allied operation, Operation Queen, to gain control of the Roer valley and of the Hürtgen Forest. The salient was a German position on the Siegfried Line (Westwall) at the boundary between the British Second Army and the American 9th Army. It restricted the movement of Allied forces and was a potential threat.