When first seen in reconnaissance photography, the large wing planform suggested an enormous and highly maneuverable fighter. This was during a period of time when U.S. design theories were also evolving towards higher maneuverability due to combat performance in the Vietnam War. The appearance of the MiG-25 sparked off serious concern in the west, and prompted dramatic increases in performance for the McDonnell Douglas F-15 Eagle in late 1960s. The capabilities of the MiG-25 were better understood in 1976 when Soviet pilot Viktor Belenko defected in a MiG-25 to the United States via Japan. The large wing turned out to be due to the aircraft's very heavy weight.
Production of the MiG-25 series ended in 1984 after completion of 1,190 aircraft. A symbol of the Cold War, the MiG-25 flew with a number of Soviet allies and former Soviet republics, remaining in limited service in Russia and several other nations. It remains the fastest combat aircraft ever produced.