The Mikoyan-Gurevich MiG-15 is a jet fighter aircraft developed by Mikoyan-Gurevich for the Soviet Union. The MiG-15 was one of the first successful jet fighters to incorporate swept wings to achieve high transonic speeds. In aerial combat during the Korean War, it outclassed straight-winged jet day fighters, which were largely relegated to ground-attack roles. In response to the MiG-15's appearance and in order to counter it, the United States Air Force rushed the North American F-86 Sabre to Korea.