This provocative book begins with a question about the Vietnam War. How is it, asks Robert D. Dean, that American policymakers-men who prided themselves on "hardheaded pragmatism" and shunned "fuzzy idealism"-could have committed the nation to such a ruinous, costly, and protracted war? The answer, he argues, lies not simply in the imperatives of anticommunist ideology or in any reasonable calculation of national interest. At least as decisive in...