In April 1943, Webster assumed command of the 42nd Bomb Wing, a unit without men or aircraft. In the Mediterranean Theater of Operations, Webster supervised the incorporation of air groups in August. He took official command on August 24, 1943. Webster commanded the unit during its participation in the Allied invasion of Italy. In July 1944, he was appointed commander of the Allied Forces in Sardinia, Italy, and deputy commander of the 12th Air Force. Going to France in March 1945, Webster assumed command of the First Tactical Air Force, a provisional unit made up of both Free French and American units.