I gratefully acknowledge David Tarr for all that he has taught me about deterrence and arms control, and Jacob Kipp for doing the same service with regard to Soviet military studies. I have learned much from Kipp and other colleagues at SASO about Soviet military history and art, including David Glantz, Bruce Menning, Harry Orenstein, Graham Turbiville and Tim Sanz. With equal gratitude I acknowledge Chris Donnelly, Peter Vigor, and Maj. Peter Podbielski of the Royal Military Academy, Sandhurst, for invaluable assistance in identifying pertinent sources and for their encouragement. Raymond Garthoff, of the Brookings Institution, has provided helpful comments on draft manuscripts and useful references in Soviet military strategy, as has Ned Lebow on the subject of crisis management. Mary Glenn, Political Science editor at Praeger, has been generous with encouragement and support; Alda Trabucchi served as production editor, and Alice Vigliani was a very thorough copy editor. Finally, I am most in debt to my wife Betsy for her patience and understanding, and to my mother for making education a matter of first importance.