Brezhnev joined the Communist Party of the Soviet Union (CPSU) in 1931 and steadily rose through the ranks, eventually becoming general secretary of the CPSU (1964-1982) and president of the USSR (1977-1982). A protégé of Nikita Khrushchev, he took power after helping engineer Khrushchev’s ouster. Brezhnev’s regime was later criticized for its corruption and failed economic policies, but the global influence of the USSR increased dramatically during his tenure, thanks in part to what doctrine? Discuss