Mikhail Gorbachev and following the Chernobyl disaster of 1986 pursued this agenda. Gorbachev's policies of "glasnost" ("openness") and "perestroika" ("restructuring") and his reorientation of Soviet strategic aims contributed to the end of the Cold War. Under this program, the role of the Communist Party in governing the state was removed from the constitution, which inadvertently led to crisis-level political instability with a surge of regional nationalist and anti-communist activism culminating in the dissolution of the Soviet Union. Gorbachev later expressed regret for his failure to save the Soviet state, though he has insisted that his policies were not failures but rather were
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