August 2, 2016–More than six decades out it is astonishing that the greatest naval battle in history has garnered as little attention as it has. This, the Battle of Leyte Gulf, was “the greatest” in lots of ways. More ships participated, more sailors, the stakes were the fates of an entire invasion fleet, the awesome combat power of one side such that its losses would be minuscule compared to those of the adversary. Measured by its decisive aspect—the tonnage of ships sunk, the destruction of virtually all of a mighty fleet—Leyte Gulf shines. For the Japanese Navy, defeat at Leyte Gulf duplicated in reverse their greatest achievement, when Japan’s fleet destroyed a Russian one at Tsushima in 1905. Apart from anything else, Leyte Gulf set the trajectory of the final phase of the Pacific War that ended with the Japanese surrender ten months later.
There is another aspect of the Leyte events which astonishes too. In this lopsided contest the Allied side held every advantage. Allied forces were far superior to the Imperial Navy’s remaining vessels, in every category of strength from battleships to submarines. Allied airpower, both carrier-based and flying from shore also far outweighed that of Japan. And Allied intelligence, photographing Japanese garrisons at will, reading Japan’s coded messages, benefitting from captured Japanese documents, saw the enemy’s cards like an open hand. Like I said, the Allies enjoyed every advantage.
In the face of all that, the Imperial Navy managed to put an immensely powerful surface force up against an isolated portion of the Allied fleet. In these days when so many speak of “asymmetrical warfare” the Leyte Gulf experience demands more attention. Now the book Storm Over Leyte meets that need in detail. One aspect of Japan’s success in getting at one fragment of the Allied fleet in isolation was a huge intelligence failure, one virtually unbelievable for the side that had attained such a great advantage.
This is only a part of the story but it is an important one. The month of October 1944 began with an Allied misreading of radio intercepts. The major Imperial Navy fleet command at mid-1944 had been the so-called “Mobile Fleet,” that had been hard hit in the Battle of the Philippine Sea (aka “Marianas Turkey Shoot”). Afterwards the Japanese had split up their forces, with the main surface units going to the Singapore area while the remnants of the aircraft carriers regrouped in the Home Islands. Messages the Allies intercepted in early October were read to indicate the Mobile Fleet had rejoined the surface force led by Vice-Admiral Kurita Takeo, Japan’s Sir Harry Hotspur for this desperate venture. That interpretation proved mistaken and U.S. intelligence realized its mistake within a few days.
Admiral Kurita had charge of the bulk of Japan’s surface combat ships. At his Lingga anchorage and in Singapore they were out of range of the usual Allied aerial reconnaissance units. The Allies could have run photo missions with China-based B-29 bombers, but the leader there, General Claire Chennault, refused. Chennault had already been pulled into agreeing to make a B-29 strike on Taiwan in support of a carrier raid there, and evidently thought he was giving the Pacific oceanic forces enough help as it was.
The window on Japanese fleet activities therefore came down to radio intelligence. Allied spooks were sharp enough that to develop a good indicator entirely by watching Japanese operating practices. They discovered that by tracking movements of Japan’s oil tankers, especially the fleet oilers needed for underway replenishment, they had a reliable predictor for naval activity. As Allied forces closed in for the Philippine invasion, the radio spies detected enemy tanker movements of the kind that indicated a fleet sortie.
But radio direction finding of messages sent by Kurita’s fleet continued to put it in the Singapore area. Allied forces in the Pacific fought an entire battle over Taiwan, conducted a series of supporting air strikes on the Philippines, and began their invasion in Leyte Gulf, without the Kurita fleet stirring. On October 16, 1944, as Allied invasion fleets closed in the spooks still located Kurita near Singapore. That same day the radio spies acquired fresh intelligence on tanker movements and began expecting Kurita to sail. The admiral actually did so on October 18 (the 17th in Washington, where the Office of Naval Intelligence, the next day, still only “expected” a fleet sortie.
Admiral Kurita headed for Brunei, a micro-state on the north coast of Borneo, where he had sent tankers to wait for him. As it happened, Allied intel authorities had previously debated the chances the Japanese would come out to fight, and the chiefs of General Douglas MacArthur’s spy unit had asked for extra aerial scouting of Brunei. A B-24 scout plane actually sighted the Kurita fleet and the Japanese monitored its contact reports monitored. But somewhere up the line the messages were misplaced and the warning lost.
Existing accounts of Leyte Gulf make much of the submarine attacks and aeronaval battles of October 24, as the Kurita fleet closed in on the Philippines, but in truth the Allies were responding instantly to reports just reaching them. Had General MacArthur and his Pacific theater opposite number, Admiral William F. Halsey, had the advance warning they could have had, the scale of their attacks would have been ferocious and Kurita might have been stopped right there.
In truth the Kurita fleet, grievously wounded during its advance toward Leyte Gulf, arrived in a weakened condition, but it pressed ahead. The next Allied element to fail would be aerial scouts over the San Bernardino Strait, a passage Kurita main force had to transit in order to reach its target. For a variety of reasons the scouts failed that night. From Pearl Harbor the Allied Pacific theater commander, Admiral Chester W. Nimitz, discovered from his radio traffic analysts that the Kurita fleet had passed the strait to debouch on the Pacific Ocean side of the Philippines. Nimitz sent messages to Halsey and other invasion commanders—revealed for the first time in Storm Over Leyte—urgently passing on the location data and identifying it as “ULTRA,” the Allied codename for its supersecret radio intelligence. Nimitz’s action could have given away the source, so they violated all the classification rules for ULTRA. The messages demonstrate his horror at the front-line situation.
The Japanese appearance was actually preceded by a series of intelligence failures—to detect by aerial reconnaissance at Lingga-Singapore or Brunei, to detect by radio direction finding at the moment of the sally, and to detect transiting the San Bernardino—to the extent that Pacific commander Nimitz felt it necessary to send messages that broke all the rules. Usually Admiral Nimitz is associated with a message that needled Halsey on the activities of his fleet, but the ULTRA messages were a far greater act of intervention. Thus our old understanding of the Battle of Samar—the action Kurita’s fleet fought off of Leyte Gulf—needs revamping.
Storm Over Leyte: The Philippine Invasion and the Destruction of the Japanese Navy (PenguinRandomHouse) is available today.