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"
Foreign trade of the Soviet Union paying above-market prices for Soviet oil. The membership of Cuba, Mongolia, and Vietnam in Comecon has served Soviet foreign policy interests more than the economic welfare of Comecon members. In general, the more economically developed European members have supported the three less developed members by providing a large market for their exports, often at above-market prices. Most of Cuba's sugar and nickel and all of Mongolia's copper and molybdenum have been imported by the Soviet Union. In addition, the Soviet Union has established naval and air bases in Cuba and Vietnam. Since 1985 Gorbachev has called for an increase in