The bitter U.S. experience in Vietnam and the pain inflicted on theSoviet Union by its Afghanistan adventure have caused Washington andMoscow to rethink the costs and benefits of unilateral military interventionon behalf of threatened clients, especially in the third world. Also, asthe Cold War winds down, the crusading spirit that has driven superpowercompetition since the end of World War II appears increasingly anachronistic.Expenditures by the superpowers in pursuit of military superiority,or even to ensure parity, are now criticized for the security theydo not provide or for detracting...