History of socialism under challenge from Solidarność, or Solidarity, a labor union under the leadership of Lech Wałęsa. The union was sufficiently threatening to the government that on 13 December 1981, the head of state, Wojciech Jaruzelski declared martial law, suspended the union, and imprisoned most of its leaders. Mikhail Gorbachev (born 1931), who took control in 1985, was the first Soviet leader to have been born after the October revolution. He is remembered for three initiatives: "glasnost", "perestroika", and the "Frank Sinatra doctrine". "Glasnost", or "openness", was Gorbachev's term for allowing public debate in the Soviet Union to an unprecedented degree. "Perestroika"
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