The MiG-31 Foxhound was the Soviet Union’s answer to emerging threats like cruise missiles, AWACS aircraft, and low-flying bombers. Equipped with a massive radar and long-range R-33 missiles, it could ...

In 1979, the MiG-31 (Foxhound) stepped forward as a Foxbat replacement (although the Foxbat continued to operate into the Gulf War with the Iraq military) and offered some compelling enhancements ...

Source: Globalsecurity.org and The National Interest. The MiG-31, which NATO calls Foxhound, made it's first flight in 1975 and was the MiG-25s successor.