On 1 April 1945, an armada of 1,321 ships gathered in the far western Pacific off Okinawa. Most had come from Leyte and Ulithi, others from Pearl Harbor, the Solomons, Sydney, and even the U.S. West Coast. They were there to land the U.S. Tenth Army—a joint Marine Corps–Army force—on this large island, part of the Ryukyus chain between Formosa and Japan. The 19 fast carriers of Task Force 58 and the British Pacific Fleet, escorted by 10 battleships, 17 cruisers, and 60 destroyers, supported the amphibious armada of escort carriers and older battleships, attack transports, and landing ships. Hundreds of mine craft, store ships, and repair vessels were present, as were netlayers, tugs, and salvage vessels.
The U.S. Navy regarded this imposing and seasoned force as unstoppable, and why not? In just a year, the U.S. Pacific Fleet had conducted a series of massive landings, including in the Marianas (winning the Battle of the Philippine Sea in the process) and on Leyte (winning the Battle of Leyte Gulf), Luzon, Iwo Jima, and now Okinawa. But the forces gathered for Operation Iceberg were even greater, a fact that is easy to overlook given the rapid pace of U.S. Navy operations.
U.S. commanders expected Okinawa to be an especially tough fight; the Navy, in particular, worried about Japan’s increasing use of “suiciders,” aircraft that deliberately crashed into their targets, with the plane itself being the weapon. But who among the Allies actually doubted victory? The U.S. Navy’s pre-invasion bombardment epitomized the basis for this confidence. At Okinawa the U.S. Navy expended 41,543 shells of 5-inch or greater size in the initial pounding of Japanese positions and 44,845 such rounds supporting the landings themselves.1
A Navy underwater demolition team diver who watched the shore bombardment from just off the beach described the sight:
The little [landing craft] lay in close behind us, their . . . machine guns pumping in perfect rhythm as they fired scant feet over our heads at the beach. Behind them the destroyers worked back and forth across their grid patterns, slamming their three- and five-inch shells in arithmetical pattern into the jungle above the shoreline. Beyond the destroyers were the cruisers and battlewagons salvoing their six- eight- and sixteen-inch guns in great bursts of fire that made their land targets jump and quiver, erupting in clouds of dust and debris.2
Previously, enemy defenses had been pummeled repeatedly by such performances; the problem for the Japanese was how to conduct meaningful resistance given the Allies’ military and technological superiority. Japan realized that, worldwide, the Axis position was collapsing and that the end was near in Europe. The U.S. strategic bombing campaign from the Marianas was under way and would reach a horrifying crescendo in March with the firebombing of Tokyo, in which the United States estimated 88,000 people died.3 U.S. Navy submarines were sweeping Japanese shipping from the vital sea lanes between the Home Islands and the Asian mainland. In early 1945, imperial headquarters could see invasion looming, but, with the army still intact and new offensives under way in China, top commanders believed total defeat was not inevitable.4
Changing Plans
So far during the war, Japan’s naval leaders had planned to overcome superior enemy military power by winning a “Decisive Battle,” such as had settled Japan’s earlier wars with China and Russia. According to the leading historians of the Japanese Navy, “The most harmful legacy of the Tsushima battle [which convinced Russia to end the Russo-Japanese War] was the conviction it instilled in Japan’s naval leaders that one great battle at sea was the essence of naval war, and that such a battle would . . . even decide the outcome of war.”5
They thought they had engineered conditions for a decisive victory—in 1942 terms—at the June 1944 Battle of the Philippine Sea. Japanese aircraft carriers launched a massive first strike at U.S. carriers from beyond the range of a U.S. counterstrike; however, this 1942-vintage formula no longer worked in 1944. Radar coupled with efficient fighter direction and control allowed U.S. Navy interceptors to cull the massed Japanese attackers repeatedly while still far from the U.S. fleet. The few bombers that broke through fell to new defensive technologies, such as proximity fuzes and radar-directed antiaircraft fire. The final numbers tell the story. On the battle’s first day, the Japanese carriers launched more than 400 aircraft and lost 346. In return, the Americans suffered minor damage to a pair of battleships, two carriers, and a heavy cruiser.
In the next Decisive Battle, at Leyte Gulf on 25 October 1944, the Japanese plan worked—if not to perfection, at least well enough. But in the ensuing engagements, the Japanese lost four carriers, three battleships, nine cruisers, and eight destroyers sunk and many more ships damaged. Leyte crippled Japan’s surface fleet and seemed to confirm that the old paradigm that had delivered victory was broken. Obtaining victory at sea using conventional forces now seemed impossible. At Leyte Gulf, the Japanese Navy achieved its best results not with 18-inch naval guns, super torpedoes, or carrier bombers, but with a few dozen piloted suicide aircraft that deliberately targeted ships. It was an act of desperation, but it seemed to work.
Facing a power that could not be defeated with the weapons at hand, operating under the hitherto unthinkable indignity of powerful and ever more deadly aerial bombardment, Japan’s leaders embraced this strategy of sacrifice. As one Japanese historian described it: “The suicide attacks [ordered in the Philippines] were initially a response to the deteriorating combat situation. On January 18, 1945, [however,] the Supreme Council for the Direction of the War made the attacks official government policy” and decided to convert “all armament production to special attack weapons of a few major types.”6
Between Leyte in October 1944 and the start of the Okinawa campaign in March 1945, kamikazes harried the U.S. fleet in gradually increasing numbers. During this time the Japanese learned that special weapons needed to be used persistently and in large numbers to make a difference. They also improved tactics. Kamikazes attacked individually or in small groups. Control aircraft directed and distributed attacks. Aircraft followed erratic courses and came in at all attitudes. These refinements made the first mass use of kamikazes during Operation Iceberg particularly dangerous.
Strategy Ashore
On Okinawa, the sacrifice strategy involved more than suicide attacks. The defending 32nd Army, which deployed three divisions and five independent formations, withdrew most troops into strong defensive positions in the island’s southern quarter instead of trying to contest the beaches or airfields. According to historian Samuel Eliot Morison, who was present on board the USS Tennessee (BB-43), Americans coming ashore were “stunned by the lack of opposition” (see “Sam Morison’s War,” February, pp. 20–25). A Japanese staff officer who had a clear view of the U.S. bombardment and the landings from a command post on the slopes of Mt. Shuri wrote how much he enjoyed watching “all this [U.S. ordnance] wasted.”7
The defenders’ minimum goal was to inflict maximum causalities and hold out as long as possible so enemy shipping would have to remain offshore supporting the ground forces. At worst, a long and bloody campaign would impress on the arrogant enemy how very costly it would be to invade the Japanese Home Islands and enable the negotiation of a reasonable peace. At best, the massive use of suicide weapons would ravage the Allied fleet and cut off the invaders’ supply, allowing the defenders to emerge from their fortifications and reconquer the island.8
In 1945, the U.S fleet was strong in ships and experience. It was enjoying the fruits of technological improvements. By April, nearly every warship destroyer-size and larger had state-of-the-art radar suites paired with a combat information center (CIC)—a facility to gather, distill, and assess input from radar, lookouts, sonar, and radio. Radar and CICs had helped the Fifth Fleet decimate Japanese carrier strikes in the Battle of the Philippine Sea. Now, nearly ten months later, training and practice had made the fleet’s air defense system even better. Nonetheless, this Japanese sacrifice strategy surprised the U.S. Navy and left it grasping for answers.
‘Smart’ Guided Weapons
In effect, the Japanese skipped years of research and development, such as produced the German Fritz X radio-guided bomb, and suddenly deployed swarms of intelligent guided weapons. Often there were too many kamikaze attacks under way for useful fighter direction or even effective plotting. The Americans, who had already adopted the practice of using radar picket ships, pushed them up to 60 miles from the beaches, but the pickets became targets themselves.
Numbers tell the tale. Between 1 April and 21 June, when Okinawa was declared secure, kamikazes delivered ten massed attacks against a background of small-scale daily raids. The first and largest attack, on 6 April, erased U.S. optimism caused by the easy landings and the rapid fall of the airfields. On that day, kamikazes sank six U.S. naval vessels and damaged 27 others.
Typical among those sunk was the USS Emmons (DMS-22). She had gone to assist the USS Rodman (DMS-21) after a kamikaze crashed into her. The Emmons’s report, written by the senior surviving officer, laconically stated: “As we supported the USS Rodman many attacks were directed at us. Tonys, Vals and Zekes were identified.” The destroyer-minesweeper claimed she “definitely splashed” six enemy aircraft “before suffering the first of five hits.”
Within minutes, “all of the hull aft of frame 175 was entirely missing and serious damage was inflicted on the port screw rendering it inoperable. The entire bridge structure was destroyed and fire raged in all spaces from frame 67 forward to gun one, from the main deck up.”9 The Emmons’s crew tried to save their ship despite suffering 64 men killed and 71 wounded, but the damage overwhelmed their efforts.
The Rodman ended up being hit three times and suffering 16 deaths. Repairs took six months.
Suicidal Attrition
The bloody battle for Okinawa dragged on another ten weeks, with dozens of vessels suffering experiences like or worse than the Emmons’s and tens of dozens like the Rodman’s. Throughout the war, the Japanese grossly overestimated the effectiveness of the attacks, and Okinawa was no exception. On 6 April, from the 32nd Army’s mountaintop command post, “more than thirty ships . . . sinking, and more than twenty burning” were observed. Believing that one more effort would break the enemy, the Japanese continued to launch mass suicide attacks, although in diminishing numbers as losses and fatigue played an increasing role.10
Although the Japanese vastly overstated the damage they caused, the reality was bad enough. On average, five of six kamikazes missed their targets, but that success rate, which was far below Japanese expectations, dismayed the U.S. command. On 6 April, Admiral Raymond Spruance, Iceberg’s naval commander, told Pacific Fleet commander Admiral Chester Nimitz that there was no good solution to the suicide attacks. On 12 April, Nimitz reported to his superior, Chief of Naval Operations Admiral Ernest King: “We are in a fight which will be hard until the Japanese run out of the means for continuing mass suicide attacks. . . . There is general agreement that we cannot seize any position northeast of Okinawa until the supply of suiciders is greatly reduced.”11
By the 16th, Spruance was becoming more emphatic, radioing Nimitz that “the scale and effectiveness of enemy mass suicide air attacks and rate of ship loss and damage are such that we must use all available means to prevent further attacks.” That same day, the amphibious commander echoed this sentiment, lamenting heavy losses in destroyer types and recommending more radar pickets, specialized fighter-director vessels, more guns, better communications, better training, and the seizure of outlying islands prior to another big landing. Other recommendations included more fighters, suppressing attacks, and use of smoke.
Some of these solutions were long term, and none could do much to mitigate, much less solve, the current crisis. As Nimitz implied on the 12th, it was a matter of hoping the Japanese ran out of aircraft before the Navy ran out of ships.12
During the Okinawa campaign, the Japanese sank 32 Fifth Fleet warships and damaged 368, as well as damaging all four British Pacific Fleet carriers. The United States lost 763 aircraft; 4,907 U.S. sailors died and 4,824 were wounded. All told, 145 vessels of all types were sunk or so damaged as to be out of action for 30 days or more. Aircraft, nearly all kamikazes, accounted for 133 of these, the balance coming from mines (4), crash boats (5), and coastal batteries (3). In the fighting ashore, the Tenth Army suffered 7,613 killed and more than 62,000 wounded (45 percent classified “non-battle”). Japanese military losses numbered up to 110,000, while civilian death estimates range from 40,000 to 150,000.13
Okinawa’s death toll horrified U.S. political leaders, especially given that planning was under way for operations against the Home Islands. The first was to be Operation Olympic, the invasion of Kyushu. It called for nine divisions—more than twice Okinawa’s initial lift—coming ashore in three widely separate locations on the first day. The Japanese anticipated a Kyushu invasion and planned that when “enemy convoys finally approached their assault destinations, all suicide forces were to launch day and night attacks which would be sustained for at least ten days. It was expected that 3,725 naval planes . . . and 2,500 army planes would be available to deliver these attacks.”
The U.S. Joint Chiefs of Staff, meanwhile, estimated that a 90-day campaign in Kyushu could cost 457,000 American casualties, including 120,000 dead. To put this number into perspective, it was ten times the U.S. causalities suffered during the three months of the Okinawa campaign. Fortunately, the United States never had to test itself against a multitiered suicide onslaught in Kyushu that would have made Okinawa seem trivial.14
A Kind of Victory
At Okinawa, the Japanese defended in an unexpected fashion, avoided the enemy’s strengths, and confronted the U.S. Navy with a weapon that challenged its best technology. Given that they successfully fulfilled their mission and helped deflect a planned invasion of the Home Islands, Okinawa’s defenders achieved a kind of victory, despite their annihilation. Okinawa also stands as the last great battle of World War II. No larger opposed amphibious operations have been conducted in the 75 years since. It is hard to think that such a massive aggregation of shipping could ever again menace a disputed beachhead.
Okinawa thus has a mixed legacy. It was the final battle of World War II and the first major amphibious operation of the modern era in which guided weapons played a major role. Japan’s “sacrifice strategy” was effective in that it influenced the U.S. decision to seek victory in ways other than invasion. This was a good thing, especially for the 700,000 U.S. and Allied servicemen who would have participated. It was less benign for many Japanese subjected to the mining and strategic bombing campaigns and to history’s only use of nuclear weapons.
What cannot be known is how many people would have died in a hard-fought invasion of the Home Islands. Had the Japanese defended Honshu as they did Okinawa, it could have been millions. British naval historian Stephen Roskill may have the last word. In 1961, he wrote: “The suicide plane was one of the most effective air anti-ship weapons developed during the war. It is indeed now plain that it brought a foretaste of the era of the guided missile.
1. Roy E. Appleman, et al., Okinawa: The Last Battle (Washington, DC: Center of Military History, 1993), 488.
2. S. E. Smith, ed., The United States Navy in WWII (New York: Quill, 1966), 938.
3. According to the U.S. Strategic Bombing Survey; other estimations top 100,000.
4. Richard B. Frank, Downfall: The End of the Imperial Japanese Empire (New York: Penguin, 2001), 89–95.
5. David C. Evans and Mark R. Peattie, Kaigan: Strategy, Tactics, and Technology in the Imperial Japanese Navy, 1887–1941 (Annapolis, MD: Naval Institute Press, 1997), 132.
6. Saburo Ienaga, The Pacific War: 1931–1945 (New York: Pantheon, 1978), 183.
7. Samuel Eliot Morison, Victory in the Pacific, vol. 14, History of United States Naval Operations in World War II (Boston: Little, Brown, 1960), 152–53; Hiromichi Yahara, The Battle for Okinawa (New York: John Wiley & Sons, 1995), xiii.
8. These issues and the overall campaign all are described well in Richard S. Lee, “Japanese Success at Okinawa,” Naval History 30, no. 3 (June 2016), 56–61.
9. Action Report and Sinking of USS Emmons (DMS-22) 6 April 1945, Record Group 38, National Archives and Records Administration, College Park, MD, 3, fold3.com/image/295921815. Both ships were converted Gleaves-class destroyers.
10. Toshiyuki Yokoi, “Kamikazes and the Okinawa Campaign,” U.S. Naval Institute Proceedings 80, no. 5 (May 1954), 508. The figure for damaged vessels is in the ballpark but four, not 30, ships were sunk.
11. Command Summary of Fleet Admiral Chester W. Nimitz (Gray Book), vol. 6, ibiblio.org/anrs/docs/D/D7/nimitz_graybook6.pdf, 3074, 3201.
12. Gray Book, vol. 6, 2861; also see 2863.
13. Joseph H. Alexander, “Hellish Prelude at Okinawa,” Naval History 19, no. 2 (April 2005). Also see Morison, Victory in the Pacific, 282, 389–92.
14. Yokoi, “Kamikazes and the Okinawa Campaign,” 512. However, it is doubtful imperial headquarters would have mustered the gasoline and fuel to carry out its plans. See Frank, Downfall, 136, 140, for casualties.
15. S. W. Roskill, War at Sea 1939–1945, vol. 3, part 2 (London: Her Majesty’s Stationary Office, 1961), 356.