Cold War (1985–1991) reduced some strategic arms unilaterally. Fundamental to the dissolution of the Soviet Union, the Gorbachev policy initiatives of Restructuring ("Perestroika") and Openness ("Glasnost") had ripple effects throughout the Soviet world, including eventually making it impossible to reassert central control over Warsaw Pact member states without resorting to military force. On June 12, 1987, Reagan challenged Gorbachev to go further with his reforms and democratization by tearing down the Berlin Wall. In a speech at the Brandenburg Gate next to the wall, Reagan stated: While the aging communist European leaders kept their states in the grip of "normalization", Gorbachev's reformist policies
Mikhail Gorbachev announced the full withdrawal of Soviet forces from Afghanistan. The withdrawal was completed the following year, although the civil war continued as the Mujahedin pushed to overthrow the pro-Soviet Najibullah government. An estimated 14,453 Soviets were killed between 1979 and 1989 as a result of the Afghanistan War. Also during 1988, Gorbachev announced that the Soviet Union would abandon the Brezhnev Doctrine, and allow the Eastern bloc nations to freely determine their own internal affairs. Jokingly dubbed the "Sinatra Doctrine" by Gorbachev's Foreign Ministry spokesman Gennadi Gerasimov, this policy of non-intervention in the affairs of the other Warsaw Pact states