In memoriam
He considered his life's work to be the book "On the Court of History: The Genesis and Consequences of Stalinism", about the Great Terror in the USSR. Together with the physicists and dissidents Andrei Sakharov and Valentin Turchin, he published an open letter to the Soviet leaders in 1970 about the need to democratize the Soviet system. He criticized the coup against Gorbachev in 1991, but also the President of Russia, Boris Yeltsin