The McDonnell Douglas (now Boeing) F-15 Eagle is a twin-engine, all-weather tactical fighter designed to gain and maintain air superiority in aerial combat. Developed for the United States Air Force, it first flew in July 1972, and is one of the most recognized modern fighters. The F-15 is expected to remain in service until 2025. Despite originally being envisaged as a pure air superiority aircraft, the design proved flexible enough that an all-weather strike derivative, the F-15E Strike Eagle, was later developed, and entered service in 1989.

Following studies in 1964-1965, the US Air Force developed requirements for an air superiority fighter in October 1965. Then on 8 December 1965, the Air Force issued a request for proposals (RFP) for the new fighter. The request called for both air-to-air and air-to-ground capabilities. Eight companies responded with proposals. In the following study phase, four of these companies developed some 500 design concepts. Typical designs featured variable-sweep wings, weighed over 60,000 lb (27,200 kg), included a top speed of Mach 2.7 and a thrust-to-weight ratio of 0.75. The designs were not accepted by the Air Force as they compromised fighter qualities for ground attack qualities. Acceptance of the Energy-Maneuverability (E-M) theory by the Air Force led to a change in requirements for improved maneuverability by the spring 1967. The design mission weight was reduced to 40,000 lb (18,100 kg), top speed reduced to Mach 2.3-2.5 and thrust-to-weight ratio increased to 0.97.

In 1967 U.S. intelligence was surprised to find that the Soviet Union was building a large fighter aircraft, known as the MiG-25 'Foxbat'. It was not known in the West at the time that the MiG-25 was designed as a high-speed interceptor, (not an air superiority fighter), so its primary asset was speed, not maneuverability. The MiG-25's huge tailplanes and vertical stabilizers (tail fins) hinted at a very maneuverable aircraft, which worried the Air Force that its performance might be higher than its US counterparts. In reality, the MiG's large fins and stabilators were necessary to prevent the aircraft from encountering inertia coupling in high-speed, high-altitude flight.

The F-4 Phantom II of the USAF and U.S. Navy was the only fighter with enough power, range, and maneuverability to be given the primary task of dealing with the threat of Soviet fighters while flying with visual engagement rules. As a matter of policy, the Phantoms could not engage targets without positive visual identification, so they could not engage targets at long ranges, as designed. Medium-range AIM-7 Sparrow missiles, and to a lesser degree even the AIM-9 Sidewinder, were often unreliable and ineffective at close ranges where it was found that guns were often the only effective weapon. The Phantom did not originally have a gun, but experience in Vietnam led to the addition of a gun. An external gun pod was tried and later the M61 Vulcan was integrated internally on the F-4E.