The author wishes to express his special thanks to Professor Ernest J. Simmons of Columbia University, whose encouragement, advice and suggestions have helped to bring this book to completion. He also wishes to express his gratitude to the Research Program on the U.S.S.R. whose material assistance has made possible the realization of the study. In addition, he wishes to thank the three translators of the work. Mr. Franklin Reeve translated Parts I and II; the late Mr. Alexander Bakshy translated Part III as far as the middle of the chapter entitled "The Debacle in the Theater”; and the rest of Part III, and all of Parts IV and the Bibliography were translated by Mr. Edgar H. Lehrman. (fragment)