Grynaviski challenges conventional wisdom by arguing that international cooperation is often the product of misunderstandings rather than shared views. Indeed, if governments knew just how distinct others’ perceptions were from their own, they would make far fewer deals. This is an intriguing argument, as counterintuitive arguments often are. Grynaviski uses the period of U.S.-Soviet détente in the early 1970s to illustrate how the outlooks each party falsely attributed to the other permitted a general easing of tensions and made possible some specific agreements, such as the 1972 Anti-Ballistic Missile Treaty. Grynaviski convincingly argues that the Nixon administration miscalculated the likely Soviet reaction to U.S. proposals and thus trapped itself into an agreement it had not originally intended to achieve. Less persuasive is the book’s larger argument about the overall positive effects such misperceptions had on the Cold War. Grynaviski concludes with a fair and lucid exploration of some explanations for détente’s ultimate failure, all of which he faults for relying too much on a single factor. He is right: but then again, the same complaint could be made about his own approach.