By the end of the Second World War the USA and Great Britain had developed viable jet fighters, even if these aircraft came a bit too late to have a significant impact on the course of the conflict. Germany achieved greater success, using the Me 262 and He 162 jet fighters operationally in the closing stages of the war. In contrast, the Soviet Union lagged behind, even though research on turbojet engines had begun in the USSR in the late 1930s. This deficiency was recognized and at the end of the war, captured German jet aircraft and engines enabled the USSR to reverse-engineer the...