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"
Communist Party of the Soviet Union The freedoms of thought and organization, which were allowed by Gorbachev, led to a rise in nationalism in the Soviet republics, indirectly weakening the central authorities. In response to this, a referendum was held in 1991, in which most of the union republics voted to preserve the union in a different form. In reaction to this, conservative elements within the CPSU launched the August 1991 coup, which overthrew Gorbachev but failed to preserve the Soviet Union. When Gorbachev returned after the coup's collapse, he resigned from the CPSU and operations were handed over to Ivashko. The CPSU was outlawed on