Sondhaus, professor of history at the University of Indianapolis, concisely and perceptively analyzes Germany’s U-boat campaign during WWI. He correctly describes the genesis of total war at sea as a response to a British surface blockade that, from the war’s beginning, was an ever-tightening noose around the Reich’s economic windpipe. The German navy’s relative ineffectiveness against its opponent further encouraged the German high command to seek an alternative—even at the risk of offending the U.S., whose economic interests were linked to the principle of freedom of the seas. Germany’s submarine force was small; its primary objective was intercepting warships, not merchantmen. Doctrine and policy for the projected campaign were embryonic, and, as Sondhaus shows, the resulting false start culminated in the 1915 sinking of the Lusitania and significantly antagonized America without seriously troubling Britain. By 1916, with the war stalemated, the German government saw ‘no alternative’ to unrestricted submarine warfare, whatever the risks of U.S. intervention. The results were immediate, Sondhaus notes: America’s declaration of war and the Royal Navy’s adaptation of ‘convoys, countermeasures, and [mine] barrages.’... [Sondhaus] persuasively demonstrates how Germany’s submarine policy cost them the war.