In early 1979 the shah fled Iran. Later that year Soviet troops moved into Afghanistan. The convergence of these alarming events posed a problem of the first order for the United States: what strategy, and what force structure, would provide the most credible deterrent to large-scale Soviet aggression in the Persian Gulf?

In this book, Joshua M. Epstein assesses the three basic strategies available to the United States: vertical escalation, horizontal escalation, and direct conventional defense. While stressing that the availability of nuclear options enhances deterrence, Epstein concludes that primary reliance on the threat of vertical or horizontal escalation would lack credibility. He then goes on to challenge the prevailing view that direct conventional defense is beyond America's reach. Through careful modeling, he shows how a U.S. rapid deployment force considerably smaller than that planned by the Reagan administration could defend successfully and deter credibly by exploiting key Soviet vulnerabilities in Iran.

Epstein 's dynamic analyses of Soviet attack options make use of military insights gleaned from Soviet General Staff documents and recently declassified U.S. war plans. These sources, he points out, reveal an uncanny agreement among American, British, and Russian military planners on a variety of Soviet weaknesses and U.S. defensive opportunities in Iran and other Southwest Asian areas.

The author's discussion of Soviet scenarios employs innovative threat-assessment and force-planning methods, detailed in a series of appendixes. These analytical techniques go far beyond the case of the Persian Gulf. The critiques of vertical and horizontal escalation, as strategies, are also of general applicability. All will prove valuable to defense planners and students and teachers of national security policy.

Joshua M. Epstein is a research associate in the Brookings Foreign Policy Studies program.