Purpose & Planning
by Jeremy Gypton
The American assault on Peleliu, in the Palau Islands, had the highest casualty rate of any amphibious invasion in terms of men and material in the entire war in the Pacific. Peleliu was viewed as a potential threat to General Douglas MacArthur's invasion of the Philippines; its airfield would enable Japanese planes to strike at American landing and support ships and menace troops once on the ground in the Philippines. Clearly, from MacArthur's perspective, the almost 11,000-man garrison there had to be eliminated before his forces could move, unhindered, on his primary target. Thus, the strategic legitimacy of the Peleliu operation was established. American amphibious doctrine – well-developed and tested from operations from the Gilberts to the Marianas – was up to the task, as well. The 1st Marine Division, a veteran of the Pacific theater, was also ready. Peleliu, however, proved to be quite different from the many previous battles in several fundamental ways, and would end with a high death toll, questionable strategic gain, and yet valuable insights for future operations.
American efforts to take back control of the Pacific and Eastern Asia from the Japanese effectively began with the Battle of the Coral Sea, and the pace of events had quickened significantly by the end of 1942. By that point, American land forces were committed in the Solomon Islands and in New Guinea, and factories back home were hard at work producing the vast fleet that would give America the reach and power to strike at multiple Japanese holdings by the end of 1943. A debate, however, raged at the highest levels of American decision-making, primarily between the army and the navy, as embodied by General Douglas MacArthur and Admiral Chester Nimitz, respectively. This debate was centered on the overall strategic approach to the war in the Pacific, and whether the approach to Japan should be made through the south, working from New Guinea to the Philippines, then on to mainland China, or through the Central Pacific, ranging from island chain to island chain, directly toward Japan itself. Both strategies had merit, and both were tenaciously championed by their proponents.
The United States, with its vast industrial and manpower base, was able to afford both strategies: MacArthur would fight his way across New Guinea and toward his dream of liberating the Philippines, and Nimitz would work his way across the Central Pacific, using the many tiny island chains there as operational stepping stones toward his goal. Peleliu, in strategic terms, was something of the midpoint between what would end up being this two-pronged approach.
The Palaus, east of the Philippines and southeast of the Marianas, were on the frontier between the advanced stages of these two American strategies, and thus would draw from one to support the other. In the months leading up to the attack, Nimitz's push through the Central Pacific had reached the Marianas and secured them after hard fighting on Saipan, Tinian, and Guam. These operations, launched in succession, had each taken longer than expected due to fierce Japanese resistance; the entire effort in the Marianas, therefore, had lasted into late August 1944.
American forces in the Southwest Pacific, meanwhile, spent the summer of 1944 securing the rest of New Guinea, a task that began with Operation CARTWHEEL in 1943. MacArthur, whose most important objective had always been the liberation of the Philippines, was now poised to launch the preliminary phases of that massive operation. First, however, he believed that the Palaus must be occupied. In addition to removing the threat posed by the Japanese airstrip and garrison to his invasion fleet, the U.S. would gain a seemingly valuable airbase to use in support of operations in the Philippines.
The first official steps taken toward what would eventually be the invasion of Peleliu began in May 1944 when Nimitz "issued a warning order for the invasion of the Palau Islands group under the codename Operation STALEMATE...[the invasion date was] set for 8 September 1944."(1) As the next logical target in the progression across the Central Pacific, the Palaus, at the distant western edge of the Caroline Islands, were home to almost 30,000 Japanese troops and 10,000 Korean and Okinawan laborers as of summer 1944.(2) These troops were spread over several of the many islands in the group, with some on the large island of Babelthuap, others on Yap, some 350 miles to the northeast, and some on Koror, also to the north of Peleliu. The Japanese 14th Division, which comprised the bulk of troops in the Palaus, was based on Koror, and commanded by LG Inoue Sadao. The division, transferred to the Palaus only in April 1944, was a veteran of several combat tours in Manchuria. Optimized for combat on the Pacific islands, the division's three regiments each had enough organic artillery and support elements to enable them to operate virtually independently of one another.
Colonel Nakagawa Kunio, commander of the reinforced 2nd Infantry Regiment of the 14th Division, was charged with preparing the defenses of Peleliu; his troops worked through summer 1944 at their task. Up to summer 1944, the Japanese had chosen to defend most other islands by arranging the bulk of their forces along the beaches, in order to break up American landings. In keeping with the accepted doctrine of favoring the attack over the defense, the Japanese sought to prepare defenses such that they would be able to move over to the offensive as quickly as possible, when the opportunity arose. According to a then-classified U.S. War Department manual entitled Handbook on Japanese Military Forces, dated 1 October 1944, "tactical doctrine insists vigorously on the inherent superiority of the offense, and [regulations] state that the offensive should be resolutely taken."(3) Although this is dated 16 days after the Peleliu invasion was launched, it is not reasonable to believe that any significant insights from that operation would have found their way into the manual, considering that it was update of a 1942 volume, and had been in the works for quite some time.
In any case, the Japanese had thus far favored the offensive so greatly that, in fact, although Japanese training manuals contained "the usual admonitions against a frontal assault"(4) it was quite common for commanders to opt for this tactic in situations which American leaders would have chosen a defensive posture. This was the sort of tactical behavior to which American leaders and troops had become accustomed since the first, frenzied banzai charges at Guadalcanal, two years before.
At Tarawa, in November 1943, the Japanese had defended at the water's edge, and resorted to frontal charges before they were defeated. Similar attacks took place throughout New Guinea, and recently in the Marshall Islands. The overall defensive methodology encountered by the Americans by late 1944 was typified by strong, but shallow, coastal defenses, enemy troops who could be expected to infiltrate through the lines wherever possible, and enemy commanders who would casually (by American standards) employ frontal assaults.
Written by Jeremy Gypton
Copyright © 2004 Jeremy Gypton