A think-tank intellectual's persuasive, if tedious, reminder that sea power confers decisive military superiority--even in an era marked by advances in aerospace, ballistic, electronic, nuclear, submarine, and allied technologies. Gray (president of the National Institute for Public Policy) is a latter-day pragmatist who coolly evaluates the evidence offered by major conflicts down through the ages. Moving back and forth in time, he assesses the nautical lessons to be learned from the Peloponnesian War; the defense of the Byzantine Empire (from about A.D. 400 through 1453); the rise and fall of Venice; the protracted strife between Great Britain and France (1688-1815); WW II; and the cold war. While many of the author's insights are buried beneath pedantic prose, offhand allusions, and academic jargon (e.g., ``environmentally specific advantage''), his geostrategic conclusions are clear enough--that control of the seas yields global mobility, with no continental parallel, for maritime forces and merchant shipping. Along similar lines, Gray argues that many Western politicians and constituencies have consistently failed to understand that the primary purpose of navies is not to engage in deep-water battles with their foes but to maintain oceanic dominion as an ``enabling agent'' of victory. Whether nonspecialists will take much interest in Gray's informed--albeit donnish and often murky--analyses, though, is quite another story.