Former Russian diplomat and chief of the K.G.B. He was appointed chairman of the K.G.B. in 1988 by Mr. Gorbachev. Mr. Kryuchkov disagreed with Gorbachev’s loosening of political and economic regulations. Kryuchkov attempted a coup against Gorbachev on August 19, 1991 with the help of a group called the State Committee for the State of Emergency. The coup fell apart, however, by August 21, 1991 due to the opposition of Boris Yeltsin, who was president of the Russian federated republic at the time. Gorbachev returned to Moscow and resumed power. Kryuchkov was arrested and charged with high treason punishable by death, but Russian parliament granted him amnesty in 1994.