Planning For The Battle of Iwo Jima - Japanese Planning

Japanese Planning

Even before the fall of Saipan in June 1944, Japanese planners knew that Iwo Jima would have to be reinforced significantly if it were to be held for any length of time, and preparations were made to send sizable numbers of men and quantities of materiel to that island. In late May, Lieutenant General Tadamichi Kuribayashi was summoned to the office of the Prime Minister, General Hideki Tōjō, and told that he had been chosen to defend Iwo Jima to the last. Kuribayashi was further apprised of the importance of this assignment when Tojo pointed out that the eyes of the entire nation were focused on the defense of Iwo Jima. Fully aware of the implications of the task, the general accepted, and by June 8, 1944, Kuribayashi was on his way to convert Iwo Jima into an impregnable fortress.

When he arrived, some 80 fighter aircraft were stationed on Iwo Jima, but by early July only four remained. A United States Navy force then came within sight of the island and bombarded it for two days, destroying every building and the four remaining aircraft.

Much to the surprise of the Japanese garrison on Iwo Jima, there was no American attempt to invade the island during the summer of 1944. There was little doubt that in time the Americans would attack, and General Kuribayashi was more determined than ever to exact the heaviest possible price for Iwo Jima, although the lack of naval and air support meant that Iwo Jima could not hold out indefinitely against an invader with sea and air supremacy.

By late July, Kuribayashi had evacuated all civilians from the island. Lieutenant General Hideyoshi Obata, commanding general of the 31st Army, early in 1944 had been responsible for the defense of Iwo Jima prior to his return to the Marianas. Following the doctrine that an invasion had to be met practically at the water's edge, Obata had ordered the emplacement of artillery and the construction of pillboxes near the beaches. General Kuribayashi had a different strategy. Instead of attempting to hold the beaches, he planned to defend them with a sprinkling of automatic weapons and infantry. Artillery, mortars, and rockets would be emplaced on the foot and slopes of Mount Suribachi, as well as in the high ground to the north of Chidori airfield.

The reason for Kuribayashi's departure from the water's edge defense strategy, which had been the normal practice for the Japanese Imperial Army, was that he predicted that American air and naval bombardments would destroy any defenses on the beaches. It had been used at Saipan to great losses for the Japanese. For water's edge defense to work, it needed support from the air and sea, none of which the Japanese Imperial Navy was capable of mounting at this point anymore. However, other military branches, especially the navy, were still insistent on the water's edge defense and demanded that Kuribayashi see to it. In the end Kuribayashi had some pillboxes built at the beach as a token measure. The pillboxes were destroyed by American bombardment.