Less than five hours after the Japanese attacked Pearl Harbor, U.S. naval leaders reluctantly chose to pursue a form of warfare they despised - targeting not only Japanese military assets but also civilian-operated fishing trawlers, freighters, and tankers. The move to unrestricted submarine warfare represented a major change in the longstanding American adherence to the classic doctrine of 'freedom of the seas,' under which commercial vessels were held to have the right to navigate the oceans without threat of attack. This dramatic about-face in naval policy, potentially as controversial as the decision to use the atomic bomb, has never been seriously challenged and, until now, closely examined. Holwitt combed archival sources from the National Archives, the Naval Historical Center, the Naval War College, Yale University, and the Franklin D. Roosevelt Presidential Library in order to reconstruct the development of both the U.S. submarine fleet and the policies for its use during World War II. As he shows in this meticulously researched book, the U.S. move to launch unrestricted air and submarine warfare against Japan was illegal. "Execute Against Japan" offers a new understanding of U.S. military policy during World War II. This thoughtful analysis will be a vital resource for military and maritime historians and professionals, as well as students of World War II.