Please note:

This plane wasn’t intended for dog-fighting. It comes from an era when bombers were still the primary means of nuclear weapons delivery and when countries around the world were deploying and studying new supersonic bombers : B-58, XB-70 project, Mirage IV, Avro 730 project, etc.

The Soviets felt the necessity to develop a fast, long-range interceptor that had to be cheap enough to be produced in large quantities. Those characteristics were dictated by the vastness of Soviet territory and the fact that NATO bombers could attack from any direction, the USSR being literally surrounded by NATO’s airfields.

US air defense didn’t have the same requirements. The only attack route for hostile bombers was Alaska and Canada, and flight time from Soviet airbases to reach populated areas in North America was very long, reducing the need for high-performance interceptors.

While jet engines at that time were ready to cope with Mach 3 speeds, the main problem when flying so fast is the intense heat that airflow generates on the fuselage, forbidding the use of classical aviation aluminium alloys.

The US decided to build the Mach 3+ recon plane SR-71 using advanced, even experimental, techniques and extensive use of titanium, a very expensive and dangerous aircraft, but unmatched in terms of performances. It was a very specialized aircraft ; very few were built (32), and more than a third was lost to accidents (12).

The Soviets had different requirements and developed a cheaper and more conventional, mainly stainless steel aircraft capable of an operational speed of Mach 2.8 while carrying missiles. It came in two flavours, interceptor and recon aircraft. At that time, very high altitude and Mach 2.5+ speeds were enough to evade most air-defense systems. It was later modernized, with more capable radar and electronics, giving birth to the MiG-31, still in use today, that found a new role as a hypersonic missile carrier.