At the beginning of Pacific Theater hostilities, the Australian and New Zealand navies were little more than coastal defense forces, with major units dispatched for service with the British navy. In the Pacific, New Zealand had 2 light cruisers and a handful of armed trawlers; Australian resources consisted of 2 heavy cruisers, 4 light cruisers, and 6 destroyers and sloops. Dutch forces, isolated from their exiled government and left on their own to protect the Netherlands East Indies, comprised 3 light cruisers, 7 destroyers, and 16 submarines.
Britain's Royal Navy had a broader (if less well-defined) role and possessed a major base at Singapore, but demands in the Atlantic and Mediterranean prevented deployment of an adequate force to fulfill that role. Until the arrival of the ill-fated battleship Prince of Wales and battle cruiser Repulse, along with 4 destroyers, at Singapore on 2 December 1941, British strength in eastern waters consisted of 3 old light cruisers and assorted smaller vessels at Hong Kong and around Malaya.
In any oceanwide conflict in the Pacific, the United States and Japan would be the principal antagonists, and by 1941 each of their navies had spent more than three decades envisioning war with the other. Both sides had to cope with the huge geographic scale on which a trans-Pacific war would be fought, necessitating a strategic array of bases and the apportioning of resources to protect them. The Japanese had not only their home island bases to defend but also the bases in islands secured after World War I and the captured facilities. The United States also had widespread and important areas to cover—its own western coastline (including Alaska), the approaches to the Panama Canal, the Hawaiian Islands (which had become its main Pacific base in May 1940), Guam, and the Philippines, guarded by the meager U. S. Asiatic Fleet. In addition, the U.S. Navy had grave responsibilities in the Atlantic.
When Japan launched its strike to neutralize the U.S. Pacific Fleet at Pearl Harbor on 7 December 1941, American naval forces in the Pacific were already numerically inferior to those of Japan in every major category. Despite mounting evidence of the critical role of naval aviation, battleships were still considered to be the core measure of naval power, and to Japan's 10 battleships the United States had 9, of which 4 were sunk and 4 others damaged in the attack on Pearl Harbor; the single remaining battleship was in overhaul at Puget Sound. Japan's 10 aircraft carriers were countered only by the Lexington, Saratoga, and Enterprise, all of which were away from Pearl Harbor on 7 December. In other categories, Japan had 18 heavy cruisers, 17 light cruisers, 111 destroyers, and 74 submarines; the United States had 13 heavy cruisers, 11 light cruisers, 80 destroyers, and 55 submarines. Included in these numbers were the 1 heavy cruiser, 2 light cruisers, 13 destroyers, and 28 submarines of the U.S. Asiatic Fleet operating from bases in the Philippines and Borneo.
With the exception of the 8 sunken or damaged battleships, 3 damaged light cruisers, and 3 damaged destroyers, all other U.S. combat vessels remained operational at the close of 7 December. From Washington's standpoint, the most dangerous imbalance between Japan and the U.S. was in aircraft carriers, but by mid-1942 the Japanese advantage had largely been offset by Japan's loss of 4 large carriers at Midway on 4–5 June. In the end, actual naval strengths at the beginning of the war mattered less than potential strengths, which were a function of industrial productivity. Here, as thoughtful Japanese strategists had known all along, Japan was no match for the United States, and the longer the war lasted, the more likely early Japanese superiority would vanish.
John A. Hutcheson Jr.
Barlow, Jeffrey G. "World War II: U. S. and Japanese Naval Strategies." In Colin S. Gray and Roger W. Barnett, eds., Seapower and Strategy. Annapolis, MD: Naval Institute Press, 1989.; Dull, Paul S. A Battle History of the Imperial Japanese Navy (1941–1945). Annapolis, MD: Naval Institute Press, 1978.; Dunnigan, James F., and Albert A. Nofi. Victory at Sea: World War II in the Pacific. New York: William Morrow, 1995.; Morison, Samuel E. History of United States Naval Operations in World War II. Vols. 2, 4, 5, 9, 10, and 11. Boston: Little, Brown, 1947–1952.; Roskill, S. W. White Ensign: The British Navy at War, 1939–1945. Annapolis, MD: Naval Institute Press, 1960.