A vivid history of an underwater craft that has proved deadlier than either battlewagons or flattops in two global conflicts and was a key part of the arsenal in one Cold War. With his customary thoroughness and Çlan, van der Vat (The Pacific Campaign, 1991, etc.) traces back to 16th-century England the concept of an oceangoing vessel that could submerge to evade or attack an enemy. While many of Europe's maritime nations tried to capitalize on this idea, more than 300 years passed before an Irish immigrant to the US named John Phillip Holland came up with a viable design. Initially, most great powers spurned the sub as a weapon of the weak, but they soon grasped its military potential and commenced substantive building programs during the prelude to WW I. The author provides an exhaustive account of the very nearly decisive roles played in this conflict by Turco-German and Austrian U-boats as well as their Allied counterparts, not only in the Atlantic but also in the Adriatic, the Black Sea, and other so- called sideshow venues. After addressing the abortive efforts at arms control and advances in submarine technology that marked the two decades between hostilities, van der Vat offers a full-dress briefing on the toll Nazi U-boats took on Anglo-American shipping during WW II. He goes on to chronicle the ruinous losses the US silent service inflicted on Japan's merchant marine and naval forces in Southeast Asian waters, then backtracks to recount how the tide was turned against the only productive arm of Hitler's Kriegsmarine, keeping Great Britain's supply lines intact. He closes with a short-take assessment of the protracted (albeit undeclared) war between the US and erstwhile USSR during which nuclear-powered subs equipped with intercontinental missiles prowled the depths. An engrossing rundown of the submarine's hell-and-high-water annals. (16 pages photos, 4 maps)