Summary Soviets utilized British jet engine to power MiG-15. British sold engines to Soviets without foresight. MiG-15 initially outperformed US jets, leading to a deadly conflict in Korea.
The Soviets copied the British Rolls-Royce Nena jet engine and used it to power the advanced MiG-15 in one of the greatest modern British technological military blunders. Militaries have always copied each other, and while the Soviets came up with a number of interesting designs of their own, they were famous for copying the West. The Tupolev Tu-4 was famously a reverse-engineered copy of the Boeing B-29 Superfortress, while the Sukhoi Su-24 was something of a copy of both the F-111 Aardvark and the French Mirage G8 .
Soviet-German jet engines were insufficient While it is well known that the Soviets and Americans took captured German scientists back with them to their countries after WW2, what is less known is that the British were also world leaders in jet technology. When the war came to an end, only the Germans and British had deployed jets in combat (the Americans and Japanese were close, but didn't). Out of the big powers, the Soviets were a noticeable laggard.
The Red Army captured German scientists, research facilities, and prototypes like the Jumo 004 and BMW 003 turbojets (designed for the Me-262 and He-162 jet fighters). The Soviets then went to work building a jet from German engines. In 1946, the year after the war, they developed the Jumo-powered Yak-15 and the BMW-powered Mi.