WILLIAM G. ROSENBERG is Professor of History at the University of Michigan. He is author of Liberals in the Russian Revolution and co-author (with Diane P. Koenker) of Strikes and Revolution in Russia, 1917. LEWIS H. SIEGELBAUM is Professor of Modern Russian History at Michigan State University. He is author of Soviet State and Society between Revolutions, 1918--1929 and Stakhanovism and the Politics of Productivity in the USSR.