The Mikoyan-Gurevich MiG-25, NATO reporting name "Foxbat", was a Cold War engineering feat, designed as a high-speed, high-altitude interceptor to counter the American XB-70 Valkyrie and SR-71 Blackbird. Uniquely constructed predominantly from nickel-steel alloy to withstand the extreme heat generated at Mach 3 speeds, the Foxbat was one of the fastest combat aircraft ever to enter service. Its large Tumansky R-15 engines provided enough thrust to propel it to an operational ceiling of over 80,000 feet. The MiG-25's appearance in the late 1960s sent shockwaves through Western intelligence communities, directly leading to the development of the American F-15 Eagle.