The introduction of the first useful surface-to-air missiles in the 1950s obviated the need for fast reaction time interceptors as the missile could launch almost instantly. Air forces increasingly turned to much larger interceptor designs, with enough fuel for longer endurance, leaving the point-defense role to the missiles. This led to the abandonment of a number of short-range designs like the Avro Arrow and Convair F-102 in favor of much larger and longed-ranged designs like the North American F-108 and MiG-25. Only the USSR seriously continued interceptor design after the 1960s, as only the USAF continued to make use of a powerful strategic bomber force.