Donald Blakeslee resigned his commission on September 13, 1940, in order to join the Royal Canadian Air Force. After training in Canada, Blakeslee began flying combat missions in England in May 1941, while assigned to 401 Squadron of the RCAF. He was credited with 3 aerial victories by the time he joined the American volunteer 133 Eagle Squadron of the British Royal Air Force as its commanding officer in July 1942. Blakeslee destroyed 2 enemy aircraft before the Eagle Squadrons were absorbed into the U.S. Army Air Forces. He became a DOUBLE ACE during World War II, and was credited with a total of 14.5 aerial combat victories. He subsequently flew combat in the Korean War before retiring in 1965 as a U.S. Air Force Colonel.