The Pacific War by John Costello

It is now easy to see how the principle cause of the breakdown  in American military intelligence during the period before Pearl Harbor was that it was grossly overloaded and unable to carry out an adequate evaluation procedures. The lessons learned brought about a rapid expansion in 1942 in both service's cryptanalysis, translation, and assessment teams. Personnel training took time, but such was the proficiency achieved by naval units that within six months they had laid the groundwork for the Midway victory. The Army succeeded in cracking the Japanese army's ciphers by the following spring and both services  contributed to the establishment of units that monitored the German Enigma traffic using the British-supplied decrypting machines. The measure of the Allied victories in battles fought and won by their code breakers is the sheer volume of the material  now piling up along the shelves in London's Public Record Office and the National archives in Washington.  The highlights of the role of Ultra - as both Britain and the United States labeled their most secret intelligence- played in the war are now known , with the Battle of Britain, Midway, the Battle of the Atlantic, El Alamein, D-Day, and New Guinea perhaps the most spectacular achievements. But it will take years for historians to sift patiently through the records  that have now become available to reveal the fascinating details of just how significant a contribution intelligence actually  played in the Atlantic and Pacific theaters - and just how much the credit that has until now been given to the most successful military commanders should in fact go to Ultra. . .

[ Not all the records have been released by the British and there are critical redactions in the American records. On those occasions in which they managed to keep their plans secret the Japanese army and navy often punished American forces severely. American strategic planners were often divided and tactics used inadequate.]

Immediately after Pearl Harbor the United States declared a policy of unrestricted submarine warfare in the Pacific. It produced limited results at first because of defective torpedoes and a lack of aggressiveness on the part of the American commanders. Misapplied use of radio intelligence was at first send to the Pacific fleet submarines chasing over the ocean after the enemy's big warships instead of concentrating on blockading Japan's main shipping routes. In the first six months the U.S. submarines sank only thirty-five Japanese merchant ships, less than ace German U-boas managed to sink in a single Atlantic patrol. Such  poor performance was reflected in the Tokyo Naval Staff's response in setting up in Formosa the "First Convoy Escort Fleet", whose over-age officers were matched by a few ancient destroyers they were assigned. Their ineffectiveness was not important, for in the whole of 1942 the Japanese lost less than 700,000 tons of shipping to all Allied submarine activity. German's were sinking that much nearly every month in the Atlantic. That year Japan's shipyards turned out over 1 million tons of new capacity, more than enough to keep pace with the attrition.


Not until the end of that disastrous first year was the American submarine campaign shaken up. Rear Admiral Charles A. Lockwood was promoted from leading the flotillas stationed at Brisbane to become Commander Submarines Pacific Fleet. After studying the reports of the U-Boat assault on British shipping lifelines in London, Lockwood soon became convinced that the poor performance of his boats, which time and again failed to sink warships or disrupt poorly protected transport convoys during the invasion of the Dutch East Indies, must be caused by a combination of defective torpedoes and lack of aggression by his captains. Experiments proved that the technical cause of the problem was the standard Mark XVII torpedoes faulty depth-keeping mechanism, which unless adjusted would causes the torpedo to pass harmlessly below the keel of the target warship. Orders were sent to compensate for the inaccurate settings, but the first months of 1943 brought no greater success.

That year Lockwood systematically replaced almost a third of the captains. When the younger, aggressive commanders' sinking rates were still not commensurate with the number of hits they claimed, it became obvious that their torpedoes were still badly defective. After Lockwood had ordered and exhaustive series of tests in Hawaii in which torpedoes were fired at cliff targets, it was found that their magnetic and contacted detonating pistols were hopelessly unreliable.


"If the Bureau of Ordinance can't provide us with torpedoes that will hit and explode, or with a gun larger than a peashooter," he blasted at a Washington conference early hat year, "then, for God's sake get the Bureau of Ships to design a boathook with which we can rip the plates off the target's sides." In spite of such caustic words and constant prodding, it was September 1943 before the first Mark XVIII torpedoes arrived for us by his Pacific submarines - and many more months before their teething troubles were finally engineered out.


Just under 1.5 million tons of Japanese merchant ships had been sunk to the bottom in 1943, but their shipyards had succeeded in providing a net gain in tankers. The beginning of 1944 saw the American submarine campaign at last begin to gain effect. Lockwood- borrowing Admiral Doenitz's U-boat tactics - organized wolf-packs of submarines directed by radio intelligence against convoys off the Luzon straits, through which many of the enemy shipping lanes funneled.  The Pearl Harbor flotillas were sent to operate from forward bases at Midway and then from the captured atolls. Success rates began to climb sharply both for the Pacific Fleet boats and those of MacArthur's naval commander, whose flotillas were reorganized at Brisbane by Rear Admiral James Fife, Jr.

The Japanese lacked the weapons, escorts, and training to provide more than token cover to the convoys, which multiplied through the spring of 1944 as troops and supplies  were rushed to the threatened island perimeter. Assembling  the merchantmen in poorly protected and ill-disciplined gaggles only made success easier for the American submarine skippers.  In January 1944  294,902 tons of Japanese shipping were sunk - the highest monthly total the war, and a clear warning to Tokyo that the assault against both their island defense and convoys was accelerating.

.   .   .   .   .  .

Capturing the island of  Peleliu  cost the live of two thousand American soldiers and Marines and many times that number of wounded. It had taken 1,589 rounds of heavy and light ammunition to kill each of  the 10,000 enemy soldiers. Such grisly statistics were attributed by the field commanders as much to the terrain as to the well-drilled defenders. It was one of the tragedies of the war that the slaughter was unnecessary. Peleliu had ceased to be a vital objective to the Americans long before the first Marine died on the Island. However, as the naval bombardment force commander Admiral J.B. Olfdendorf observed: "If military leaders were gifted with the same accuracy of foresight that they are with hindsight, undoubtedly, the assault and capture of the Palaus would never have been attempted."

Never-the-less, Douglas MacArthur openly criticized the 'awful way" in which Admiral Nimitz sacrificed thousands of American lives to capture the whole of an island when he only needed its airfields.

[ The prospect of such wasteful expenditure of American lives in capturing the Japanese homeland, securing 'unconditional surrender' and hastening a conclusion to the war led, in part, to the decision drop the A-Bomb. There were extrinsic considerations- intimidating the Russians, for one, though they had already obtained the means to build their own bomb by 1945.  The complete destruction  the Japanese Navy and blockade of its ports, continued firebombing of cities and more vigorous diplomatic initiatives would, in my and others' estimation would have been sufficient without an invasion.]