They Soviets stressed Quantity Over Quality.
The pilots knew the planes were junk. The MIG-20 was so shoddy they would actually come apart at high speed and high altitudes if they made any sudden maneuvers. And some did when ‘chasing’ the SR-71.
The Mig-25 was a flying fuel tank, built especially for intercepting the SR-71. But couldn’t................
“Built especially for intercepting the SR71”
From ‘MIG Pilot’ Victor Belenko’s biography, he mentions the B-70, which he was briefed on, and was told there was a ‘special project’ that would take care of that. That became the MIG 25.
Thought I read the Mig 25 was in anticipation of the B-70?