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Execute Against Japan:  The U.S. Decision to Conduct Unrestricted Submarine Warfare

 By Joel Ira Holwitt. 262 pp. Texas A&M University Press, 2009. $37.50.

 From the nation’s founding, “freedom of the seas”—the right of civilian vessels to ply the oceans without interference by belligerents—constituted a bedrock principle of American foreign policy. At 5:52 p.m. Eastern time on December 7, 1941, Adm. Harold Stark, chief of naval operations, issued an order that reversed that right: “Execute against Japan Unrestricted Air and Submarine Warfare.” In “Execute Against Japan” Joel Ira Holwitt, a U.S. Navy submariner, delivers an impressive account of how Stark formulated that order, which authorized American submarines to attack merchant vessels without warning, and in doing so, proved critical to their success.

Under international law prior to the submarine’s advent, a belligerent’s warships could stop neutral merchant vessels suspected of transporting combatant-bound material useful for war. If found, contraband could be seized; the merchant ship itself might be seized or even sunk, and its passengers taken prisoner. As the Germans discovered in World War I, these “cruiser rules” were completely impractical for submarines—which, unlike typical surface warships, possessed limited crew or capacity to conduct boarding operations and were extremely vulnerable on the surface. Worse yet, Britain armed its merchant vessels. Even a single gun posed a vastly greater threat to a sub than it would to a surface ship.

Modest efforts to adjust this legal regime to account for the practical realities of submarine operations failed, and after World War I, the United States entered into treaties—still binding in December 1941—which subjugated subs to “cruiser warfare” rules. As a shrewd September 1935 article by Hyman G. Rickover (then a lieutenant commander) noted, by inequitably granting equal immunities to armed and unarmed merchant vessels, the treaty rendered cruiser rules impracticable for subs. He predicted, correctly, that failure to address the issue of armed merchant vessels meant the treaty would be ignored.

As Holwitt details the intriguing story, Admiral Stark and his chief war planner, Rear Adm. Richmond Kelly Turner, quietly maneuvered U.S. Navy policy toward unrestricted submarine warfare in the year prior to Pearl Harbor. The process began in December 1940 with the issue of War Plan Rainbow 3, which authorized the commanders of the Pacific and Asiatic fleets to designate “strategical areas” from which they could bar all merchant vessels—or capture, not sink, those that ventured there. Then in February 1941 Stark answered a pointed inquiry from the Asiatic Fleet commander, Adm. Thomas Hart, by saying Hart could assume Japan’s military controlled all merchant shipping in the strategical areas. With this, Stark sanctioned the blanket presumption that all shipping in the designated area was not neutral, and hence subject to unrestricted sub warfare.

At the same time, the Naval War College independently concluded that the rules of engagement governing U.S. subs were outdated and impractical. It advocated a path that helped point Stark and Turner toward an even more sweeping authorization. By September 1941, the two men resolved not only to authorize unrestricted submarine warfare against Japan, but to do so upon war’s outbreak, without waiting for justification to frame the order as retaliation for Japanese international law violations.

In October 1941, Turner instructed Comdr. James Fife, a staff officer headed to the Asiatic Fleet submarine force, to inform Admiral Hart that the navy department would authorize unrestricted submarine warfare against Japan within one week of hostilities’ commencement. On November 27, Stark directly informed Hart that he would grant him authorization immediately once war began—which is exactly what Stark did on December 7, 1941.

Only one flaw and one reservation arise from this otherwise excellent work. Holwitt concludes that Hart authorized unrestricted air and submarine warfare against Japan more than three hours before Stark issued the order. If so, Hart would have grossly violated Stark’s instructions to wait for official sanction from Washington before putting into effect a huge and historic change in national policy. An independent review of the actual message form with Hart’s order and the Asiatic Fleet’s war diary, however, demonstrates that Hart transmitted his order after Stark’s authorization arrived. Holwitt does make a solid case that there is no documentary evidence that Stark and Turner ever discussed this order with Frank Knox, the secretary of the navy, or with President Roosevelt, so he is fully entitled to conclude that these officers violated the principle of military subordination to civilian leadership. But anyone who reviews the massive flow of information to Roosevelt about even the smallest details of navy activities, and considers the president’s penchant for security and what became known as “deniability,” will hesitate to rule out discussion of so weighty a matter.

One final point: although the policy of unrestricted air and submarine warfare proved critical to the Pacific war’s course, this splendid work is the first comprehensive account of its origins— illustrating that historians have by no means exhausted questions about this conflict.


Originally published in the November 2009 issue of World War II. To subscribe, click here