The Marine components staged for Iceberg in scattered locations. The 1st Marine Division, commanded by Major General Pedro A. del Valle, had returned from Peleliu to “pitiful Pavuvu” in the Russell Islands to prepare for the next campaign. The 1st Division had also been the first to deploy to the Pacific and had executed difficult amphibious campaigns at Guadalcanal, Cape Gloucester, and Peleliu. At least one-third of the troops were veterans of two of those battles; another third had experienced at least one. Tiny Pavuvu severely limited work-up training, but a large-scale exercise in nearby Guadalcanal enabled the division to integrate its newcomers and returning veterans. General del Valle, a consummate artillery officer, ensured that his troops conducted tank-infantry training under the protective umbrella of supporting howitzer fires.
The 6th Marine Division became the only division to be formed overseas in the war when Major General Lemuel C. Shepherd, Jr., activated the colors and assumed command in Guadalcanal in September 1944. The unit may have been new, but hardly a greenhorn could be found in its leadership ranks. Many former Mariner raiders with combat experience in the Solomons comprised the heart of the 4th Marines. The regiment had also landed at Emirau and Guam. The 22d Marines had combat experience at Eniwetok and Guam. And while the 29th Marines comprised a relatively new infantry regiment, its 1st Battalion had played a pivotal role in the Saipan campaign. General Shepherd used his time and the more expansive facilities on Guadalcanal to conduct progressive, work-up training, from platoon to regimental level. Looking ahead to Okinawa, Shepherd emphasized rapid troop deployments, large-scale operations, and combat in built-up areas.
The 2d Marine Division, commanded by Major General LeRoy P. Hunt, had returned to Saipan after completing the conquest of Tinian. There the division absorbed up to 8,000 replacements and endeavored to train for a frustratingly varied series of mission assignments as, in effect, a strategic reserve. The unit already possessed an invaluable lineage in the Pacific War—Guadalcanal, Tarawa, Saipan, and Tinian—and its mere presence in Ryukyus’ waters would constitute a formidable “amphibious force-in-being” which would distract the Japanese on Okinawa. Yet the division would pay a disproportionate price for its bridesmaid’s role in the coming campaign.
The Marine divisions preparing to assault Okinawa experienced yet another organizational change, the fourth of the war. Headquarters Marine Corps (HQMC), constantly reviewing the lessons learned in the war to date, had just completed a series of revisions to the tables of organization and equipment for the division and its components. Although the “G-Series” T/O would not become official until a month after the landing, the divisions had already complied with most of the changes. The overall size of each division increased from 17,465 to 19,176. This growth reflected the addition of an assault signal company, a rocket platoon (the “Buck Rogers Men”), a war dog platoon, and—significantly—a 55-man assault platoon in each regimental headquarters. Artillery, motor transport, and service units received slight increases. So did the machine gun platoons in each rifle company. The most timely weapons change occurred with the replacement of the 75mm “half-tracks” with the newly developed M-7 105mm self-propelled howitzer—four to each regiment. Purists in the artillery regiments tended to sniff at these weapons, deployed by the infantry not as massed howitzers but rather as direct-fire, open-sights “siege guns” against Okinawa’s thousands of fortified caves, but the riflemen soon swore by them.
Headquarters, U.S. Marine Corps, backed up these last-minute changes by providing the quantities of replacements required, so that each assault division actually landed at full tables of organization (T/O) strength, plus the equivalent of two replacement drafts each. Sometimes the skills required did not match the requirement, however. Some of the artillery regiments had to absorb a flood of radar technicians and antiaircraft artillery gunners from the old Defense Battalions at the last moment. But by and large, the manpower and equipment shortfalls which had beset many early operations had been overcome by the time of embarkation for the Okinawa campaign.
Surprisingly for this late in the war, operational intelligence proved less than satisfactory prior to the Okinawa landing. Where pre-assault combat intelligence had been superb in the earlier operations at Tarawa (the apogean neap tide notwithstanding) and Tinian, here at Okinawa, the landing force did not have accurate figures of the enemy’s numbers, weapons, and disposition, or intelligence of his abilities. Part of the problem lay in the fact that cloud cover over the island most of the time prevented accurate and complete photo-reconnaisance of the target area. In addition, the incredible digging skills of the defending garrison and the ingenuity of the Japanese commander conspired to disguise the island’s defenses.
OKINAWA SHIMA
Showing Principal Roads, Towns, and Villages
The island of Okinawa is 60 miles long, but only the lower third contained the significant military objectives of airfields, ports, and anchorages. When Lieutenant General Mitsuru Ushijima assumed command of the Thirty-second Army in August 1944, he quickly realized this and decided to concentrate his forces in the south. He also decided, regretfully, to refrain from contesting the likely American landings along the broad beaches at Hagushi on the southwest coast. Doing so would forfeit the prize airfields of Yontan and Kadena, but it would permit Ushijima to conserve his forces and fight the only kind of battle he thought had a chance for the Empire: a defense in depth, largely underground and thus protected from the overwhelming American superiority in supporting arms. This was the attrition/cave warfare of the more recent defenses at Biak, Peleliu, and Iwo Jima. Each had exacted a frightful cost on the American invaders. Ushijima sought to duplicate this philosophy in spades. He would go to ground, sting the Americans with major-caliber gunfire from his freshly excavated “fire-port” caves, bleed them badly, bog down their momentum—and in so doing provide the Imperial Army and Navy air arms the opportunity to destroy the Fifth Fleet by massed kamikaze attacks.