The following article on Japanese strategy in Pearl Harbor is an excerpt from Barrett Tillman's book On Wave and Wing: The 100 Year Quest to Perfect the Aircraft Carrier.
Japanese strategy in Pearl Harbor was based on relying on naval airpower over land-based planes. This is a customary approach to war today, but in 1941 it was a radically new form of warfare that challenged conventional wisdom in the still-early days of aerial combat.
The oceanic route to Pearl lay along a tangled path of diplomatic, military, and economic concerns. Japan, increasingly aggressive, began fighting China off-and-on in 1931, going at it full time starting in 1937. Tokyo's aggression continued unchecked, and in 1941 it seemed aimed elsewhere-notably French Indochina and the Dutch East Indies. President Franklin D. Roosevelt took action, ordering an oil embargo in July, and the next month Washington warned the Japanese of possible consequences if they attacked nations beyond China.
Tokyo took little heed. Determined to avoid capitulation to what they considered foreign extortion, the cabinet of General Hideki Tojo opted for war. With less than two years of oil reserves, Tokyo had to act quickly and decisively.
Enter the aircraft carrier. It was the lynchpin of Japanese strategy in Pearl Harbor.
Admiral Isoroku Yamamoto had risen to command the Combined Fleet in August 1939, days before the new war in Europe. An aviation advocate, he had supported Japan's carrier program and, once committed to war, he backed the Hawaii Plan as preferable to the doctrinal “decisive battle” in mid-Pacific. He knew America well, having served there twice between the wars, and he realized that a pre-emptive strike was essential to the success of Japanese strategy in Pearl Harbor-if success were possible at all.
Intensive training began in late August, affording Nagumo's aircrews barely three months to perfect Japanese strategy in Pearl Harbor. Genda's plan involved a triple blow: high-altitude level bombers, dive bombers, and torpedo planes. The Imperial Navy was well versed in all three, but Pearl Harbor presented a problem: the average depth was barely forty feet, and Japanese torpedoes needed twice as much to recover, rise to the desired depth, and run safely.
Ordnance engineers found an inspired solution. Large wooden surfaces were fitted to the torpedoes' standard fins, providing larger surface areas. Once in the water the wooden fins were released and the Type 91 torpedoes sped on their way. Last-minute tests confirmed the theory.
On the morning of Sunday, December 7, 1941, the aircraft carrier was much like the proverbial musician who works twenty years to become an overnight sensation. When the Imperial Navy stunned the world with the attack on Pearl Harbor, Japan and the United States had two decades of experience operating carriers, perfecting equipment and techniques; thus it was no surprise that Japanese strategy in Pearl Harbor was so advanced. Both navies had commissioned their first flattops in 1922, and they had experienced a parallel development.
The six Japanese carriers bound for Hawaiian waters were arrayed in pairs: the giant sisters Akagi and Kaga in the First Carrier Division; Soryu and Hiryu in the Second; and newly commissioned Shokaku and Zuikaku in the Fifth. They embarked some 420 bombers, torpedo planes, and fighters, while battleships and cruisers operated catapultlaunched floatplanes. The carriers were escorted by two battleships, three cruisers, nine destroyers, and nourished by seven tankers. The latter were more important than the fourteen escorts, as the striking force could not reach Hawaiian waters and return without replenishing at sea.
Kido Butai sortied from the Kurile Islands on November 26. Crossing the North Pacific under radio silence, the task force avoided detection during the ten-day transit. Meanwhile, submarines had already departed home waters and bases in the Marshall Islands.
Japanese strategy in Pearl Harbor was well-planned but at the same time put together at the last minute. Emperor Hirohito had approved war against the Western powers barely a month before the attack, but he did not grant approval for the Hawaii operation until December 1. Thus, Nagumo's force represented an arrow launched at the heart of the U.S. Pacific Fleet that might have been recalled in flight. Instead, it flew straight to its target.
The first wave was timed to arrive over Pearl about thirty minutes after Japanese diplomats delivered Japan's refusal to accept Washington's demands. But the message from Tokyo took too long to decode, so the mission proceeded as a surprise. The attack precipitated boiling anger throughout America, fueling a surging rage that never abated until V-J Day.
While the leading squadrons winged southward, Kido Butai continued as briefed. At 7:15 the second wave of 168 planes lifted off its decks, comprising fifty-four level bombers, seventy-eight dive bombers, and thirty-six fighters.
“TORA, TORA, TORA!”: Japanese Strategy in Pearl Harbor Unfurled
Leading the first wave over Pearl Harbor was Lieutenant Commander Mitsuo Fuchida, Akagi's senior aviator. Flying as observer in a Nakajima B5N horizontal bomber, he issued the order to proceed with the attack, as described in his memoir:
One hour and forty minutes after leaving the carriers I knew that we should be nearing our goal. Small openings in the thick cloud cover afforded occasional glimpses of the ocean… Suddenly a long white line of breaking surf appeared directly beneath my plane. It was the northern shore of Oahu.
Veering right toward the west coast of the island, we could see that the sky over Pearl Harbor was clear. Presently the harbor itself became visible across the central Oahu plain, a film of morning mist hovering over it. I peered intently through my binoculars at the ships riding peacefully at anchor. One by one I counted them. Yes, the battleships were there all right, eight of them! But our last lingering hope of finding any carriers present was now gone. Not one was to be seen.
It was 0749 when I ordered the attack. The radioman immediately began tapping out the pre-arranged code signal: “TO, TO, TO… ”
Leading the whole group, Lieutenant Commander Murata's torpedo bombers headed downward to launch their torpedoes, while Lieutenant Commander Itaya's fighters raced forward to sweep enemy fighters from the air. Takahashi's dive-bomber group had climbed for altitude and was out of sight. My bombers, meanwhile, made a circuit toward Barbers Point to keep pace with the attack schedule. No enemy fighters were in the air, nor were there any gun flashes from the ground.
The effectiveness of our attack was now certain, and a message, “Surprise attack successful!” was accordingly sent to Akagi at 0753. The message was received by the carrier and relayed to the homeland.
Mitsuo Fuchida ended the war as a captain. Subsequently he became a Christian evangelist, spending much time in the United States. He died in 1976.
Once Fuchida signaled “Tora, tora, tora,” the Japanese strategy in Pearl Harbor proceeded largely as planned. The first B5Ns over the target were sixteen from Soryu and Hiryu. Briefed to hit carriers on Ford Island's northwest coast, they went for alternate objectives, destroying the target ship USS Utah (née BB-31, re-designated AG-16) and damaging a cruiser.
Akagi's torpedo squadron led a devastating attack. The Nakajimas swept in from the north shore of the harbor, skimming low between Hickam Field and the fuel tank farm, then nudging downward over the water. Making one hundred mph at sixty-five feet, they deployed as per individual briefings and turned onto their attack headings. A quarter mile ahead lay the gray monoliths along Battleship Row.
Of thirty-six torpedoes dropped, probably nineteen found their targets. Hardest hit were West Virginia (BB-48) and Oklahoma (BB-37) moored outboard at the head of Battleship Row. California (BB-44), resting farther ahead of the others, drew further attention and took two hits and slowly settled onto the mud.
Five torpedo planes were shot down, all from succeeding waves as the defenders responded and fought back. After-action reports showed that most ships began returning fire within two to seven minutes.
The high-level B5Ns each carried an 800 kg armor-piercing bomb, designed to penetrate a battleship's thick armor. The ten planes targeting Arizona (BB-39) scored four hits and three near misses. One of them found the sweet spot, smashing into Arizona's forward magazine. The 1,760-pound weapon ignited tons of gunpowder, destroying the ship in seconds with three-fourths of the crew.
At 8:40, almost half an hour after the first attack, 167 aircraft of the second wave were led by Zuikaku's senior aviator, Lieutenant Commander Shigekazu Shimazaki. No torpedo planes participated, but fifty-four Nakajima level bombers struck three air bases. The seventy-eight Aichi dive bombers were assigned any carriers in port with cruisers as secondary goals. Nearly three dozen Zero fighters established air superiority over Hickam and Bellows Fields plus Kaneohe Naval Air Station.
Much of the effort was wasted as many dive bomber pilots probably misidentified ship types; perhaps twenty-eight Aichis dove on destroyers or auxiliary vessels. The brunt of the second dive bombing attack was Nevada (BB-36), the only battleship to get underway. Already holed by a torpedo, she took six bombs in a few minutes and developed a list. To avoid sinking, she was beached near the harbor entrance.
When the second wave departed northward, the entire attack had lasted not quite two hours, from 7:55 to 9:45. In their slipstream the Japanese left Oahu stunned, both physically and emotionally. The attack killed 2,335 U.S. military personnel and 68 civilians.
Combined Army-Navy-Marine aircraft losses were about 175 immediately assessed as destroyed plus twenty-five damaged beyond repair. Some 150 sustained lesser damage.
The Japanese lost twenty-nine aircraft and sixty-five men, mostly aircrew, but including ten sailors in five miniature submarines.
Far at sea, at 11:15 Kido Butai began landing the second wave, completed an hour later. The fliers were jubilant. They knew they had inflicted severe damage and were eager to complete the task. But Nagumo opted for prudence. More than one hundred returning planes were damaged to varying extents, and most critically he needed to conserve fuel oil. The Imperial Navy had too few fleet tankers in 1941 and never caught up. Nagumo turned for home, with Second Carrier Division diverting to attack Wake Island.
Pearl Harbor was a rarity in history-a clearly defined day when the old order ended, abruptly, violently, and permanently. Not only had Kido Butai initiated a new way of warfare, but it upset the conventional wisdom that naval airpower could not compete with land-based planes. Japanese strategy in Pearl Harbor was a complete disruption of aerial combat. Historian John Lundstrom did not exaggerate when he described Kido Butai as “a 1941 atomic bomb.” But retribution was coming.
Of the twenty-nine ships that had departed Japan, one escaped destruction over the next four years. The destroyer Ushio, among those diverted en route to shell Midway, survived the Solomons bloodletting and Leyte Gulf and was surrendered at Yokosuka in 1945.
By then, U.S. aircraft carriers had turned the world's greatest ocean into an American lake.
This article is part of our larger selection of posts about the Pearl Harbor attack. To learn more, click here for our comprehensive guide to Pearl Harbor.
This article is an excerpt from Barrett Tillman's book On Wave and Wing: The 100 Year Quest to Perfect the Aircraft Carrier.
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