FDR - Jean Edward Smith [333]
Yamamoto’s experience provided a unique perspective on modern warfare. Though not a pilot, he was closely associated with naval aviation, having been executive officer of the Navy’s flight school in the mid-1920s, commander of the First Carrier Division in the early 1930s, director of the Aeronautical Department of the Navy from 1935 to 1936, and vice minister from 1936 to 1939. Like Brigadier General William “Billy” Mitchell in the United States, he was a champion of airpower; unlike Mitchell, Yamamoto possessed the rank, prestige, and administrative skill to do something about it. In the Navy he was known as a bold, original thinker and an inveterate gambler. He thrived on all-night poker games, testing his opponents’ nerves, endurance, and patience—just as he tested himself. “In all games Yamamoto loved to take chances just as he did in naval strategy,” explained his administrative aide, Captain Yasuji Watanabe. “He had a gambler’s heart.”105
The war plan Yamamoto inherited in 1939 envisaged a decisive naval battle with the American fleet near the home islands in which land-based planes and submarines would whittle down the U.S. armada until the Imperial Navy took it on in an old-fashioned line-of-battle slugfest. Yamamoto recognized that strategy was inadequate to support an all-out southward thrust against numerous objectives several thousand miles away. The U.S. Navy would have to be destroyed at the outset if the long, exposed Japanese flank were to be secured.106
When Yamamoto first thought of attacking Pearl Harbor is unclear. The British victory at Taranto on November 12, 1940, in which twelve carrier-based torpedo planes surprised the Italian fleet lying at anchor and sank three battleships, focused his attention on the possibility.107 In his own correspondence, Yamamoto suggests that planning began in December 1940, first as a concept, then a plan, finally as an exercise, including repeated mock attacks on a model of Pearl Harbor set up in Japan’s Kagoshima Bay. The logistical problems were enormous. To mass the necessary number of planes (Yamamoto estimated 300) would require a task force of at least six carriers, and the 3,500-mile attack route—well beyond the fleet’s cruising range—would require tricky refuelings at sea.* But the most difficult problems were tactical: first, to ensure complete surprise; then to launch a torpedo attack in the shallow waters of Pearl Harbor. The Italian anchorage at Taranto, by contrast, was in deep water, and the general view in naval circles was that aerial torpedoes required a depth of at least 12 fathoms (72 feet), otherwise they would hit bottom, lodge in the mud, or explode prematurely. The American Navy was so convinced that was the case that it rejected the use of antitorpedo nets at Pearl Harbor as unnecessary.108 By October 1941 the Japanese had developed a finned torpedo that could run in 6 fathoms (36 feet), and by November had perfected a launch technique with pilots flying at 100 knots (roughly 115 mph) and an altitude of 60 feet that guaranteed an 83 percent success rate.109
As finally written, Yamamoto’s attack plan had eight interlocking components, of which the attack on Pearl Harbor was the centerpiece. Additional formations moved against the American Asiatic Fleet in the Philippines, against the British off Singapore, and the Dutch near Borneo. Invasion forces, some comprised of more than a hundred vessels, steamed independently