This Pacific Battle Meant Japan's Days Were Numbered

Two Marines from the 2nd Battalion, 1st Marine Regiment during fighting at Wana Ridge during the Battle of Okinawa, May 1945. U.S. Army/Staff Sergent Walter F. Kleine.
June 21, 2020 Topic: History Region: Asia Blog Brand: The Reboot Tags: World War IIPacific TheaterImperial JapanOkinawaU.S. Marines

This Pacific Battle Meant Japan's Days Were Numbered

The savage final land battle between “the eagle and the sun” was America’s longest and bloodiest campaign in the Pacific Theater.

As one island or island group in the Pacific was fought over by American and Japanese forces, it became clear that Japan’s days as a combatant in World War II were numbered. One after another, these Imperial outposts fell to the Americans, who were clawing their way ever closer to the Japanese home islands.

 

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Just as Nazi Germany could only be defeated by the Allies seizing one mile after another on their way to Berlin, American planners had looked at the maps of the Pacific and plotted a roadmap across vast stretches of ocean, with the arrows all pointing at Tokyo.

Beginning in August 1942, at Guadalcanal, the war in the Pacific had been a bloodbath as American forces wrestled one tropical island after another from a tenancious enemy for whom the word “surrender” was the equivalent of “dishonor.” After the Americans, near the end of 1943, had seized the Gilbert Islands of Tarawa, Makin, and Apamama, the Marshall Islands were next in the crosshairs. The islands of Kwajalein, Majuro, and Eniwetok were taken, opening the sea lanes for further battles in the Marianas, where the defenders of Saipan, Tinian, and Guam waited to be slaughtered.

In the waters around the Philippines, huge naval and aerial battles erupted, and the Japanese were soundly defeated. Still the Japanese refused to give up, and so the American juggernaut rolled on, unchecked, crushing opposition at tiny places with such unfamiliar names as Peleliu and Angaur in the Palau Islands. More islands would continue to fall like dominoes—Biak, Noemfoor, Morotai—each one bringing the Americans and their devastating Boeing B-29 Superfortress heavy bombers closer to Japan.

Although islands such as Mindanao and Formosa were on the American hit list, they would be bypassed, their garrisons cut off and allowed to wither in favor of other, more strategic islands. On October 3, 1944, American commanders in the Pacific received orders to attack and seize Japanese-held territory in the 620-mile-long Ryukyu chain of islands that extend southward from Kyushu, Japan’s southernmost home island. The main island in the Ryukyus, located almost midpoint in the chain, is named Okinawa.

A new operation was conceived to invade Okinawa. Its code name: Iceberg.

In a top-level command conference on December 12, 1944, Japanese military leaders in Tokyo pondered the next move of their American opponents on the vast ocean highway leading to the home islands: Formosa or Okinawa? Japanese martial doctrine asserted “decisive battle” to defeat their enemy, both on land and at sea, and Okinawa seemed their best bet to inflict both as 1945 was about to dawn.

For their part, the Allies coveted strategic Okinawa as the final staging point for the projected twofold invasion of the Japan homeland itself—Operation Downfall and its twin parts, Operations Olympic (the attack on Kyushu) and Coronet (the invasion of the main island of Honshu).

Japanese Emperor Hirohito’s generals and admirals saw the coming island battle as their last chance to destroy the invading enemy before the home islands could be ground under the foe’s iron heel from the west. Thus, for both sides, Okinawa was to become the crucial battle of the entire war. It would also be the largest and costliest land battle of the Pacific campaign.

Indeed, due to the later two American atomic bomb attacks that ended the war in sudden flashes, the fight for the island fortress was to be the last such ground combat between them.

Okinawa is a rugged, mountainous island, a scant 350 nautical miles south of Japan’s sacred home islands. The Japanese landed on the island in 1609. When American Navy Commodore Matthew C. Perry landed there with his “black ships” in 1853 on his way to Japan, he called Okinawa “the very door of the Empire.” He recommended that the U.S. fleet establish a base there. Okinawa was annexed to Japan proper in 1879, and in 1945 it was included in the 47 Japanese administrative prefectures.

The Japanese began to build up their defenses—artillery positions, bunkers, trenches, caves, tunnels, spider holes, and minefields—on the island in 1944. Imperial Lt. Gen. Mitsuru Ushijima—nicknamed the “Demon General”—was given command of the 877-square-mile “ocean island fortress” of Okinawa in August 1944. The island was defended by the 32nd Army, about 120,000 men strong. This initially encompassed the following units of the Imperial Japanese Army: the 9th, 24th, and 62nd Divisions, as well as the 44th Independent Brigade.

However, the loss of the 9th Division to shore up defenses in the Philippines before the start of the Okinawa battle forced Ushijima to enlist many native home-guard units from Okinawa proper to bolster his ranks. In March 1945, American intelligence estimated 53,000-56,000 enemy troops stationed on the island; shortly before the invasion, this number was upped to 65,000.

In actuality, Ushijima had 77,000 Army troops at his command: 39,000 infantry combat troops and 38,000 “special troops” from artillery and other units. These included 20,000 Boeitai (drafted militia) native Okinawans, 15,000 nonuniformed laborers, 15,000 students in Iron and Blood Volunteer Units, and 600 more students in a nursing unit.

Mitsuru Ushijima was one of Japan’s most experienced commanders. He was born on July 31, 1887, in Kagoshima City, Japan, and graduated from the Imperial Japanese Army Academy in 1908, and from the Army Staff College in 1916 during World War I.

He took part in the Siberian Intervention and the Second Sino-Japanese War between the two world wars as well. A brigade and divisional commander between the world wars, Ushijima also was commandant of the elite Toyama Army Infantry School and in 1939 was promoted to the grade of lieutenant general.

During the early part of World War II, Ushijima commanded troops in China and Burma. He again became a commandant—both of the NCO Academy and the Army Academy—during 1942-1944.

Despite his rather gruff nickname, this Japanese commander was described as being a humane man who discouraged his senior officers from striking their subordinates and who disliked displays of anger because he considered it a base emotion. According to staff members, Ushijima was a calm and capable officer who evoked confidence among his soldiers.

In contrast to Ushijima was his temperamental chief of staff, Army Lt. Gen. Isamu Cho, termed “Butcher” Cho by author David Bergamini. Cho served Japanese Prince Asaka in that same capacity during the brutal “Rape of Nanking” in China in 1937, during which thousands were slaughtered (See WWII Quarterly, Fall 2011).

Isamu Cho was born on January 19, 1895, in Fukuoka Prefecture, Japan. He graduated from the Army Academy in 1916 and the Staff College in 1928. His early military service was in the radically politicized Kwantung Army in eastern China, and he also took part in several right-wing Army coups against civilian politicians in Japan.

His later service included tours of duty in the puppet state of Manchukuo, on the frontier with the Soviet Union, on the island of Formosa, and in Indochina.

During 1942-1944, Cho commanded the 10th Division. He was promoted to lieutenant general in 1944 before becoming chief of staff to Ushijima’s 32nd Army. In basic disagreement with his commander’s defensive shugettsu (bleeding) strategy, he felt that all-out aggressive action was the only way to defeat the Americans.

A violent man who both smoked and drank too much, Cho was known for slapping subordinates. While ruthlessly seizing all civilian food supplies for his troops, Cho asserted, “The Army’s mission is to win, and it will not allow itself to be defeated by helping starving civilians.”

Colonel Hiromichi Yahara was the talented operations officer of Ushijima’s 32nd Army. Born October 12, 1902, he joined the Army in 1923, teaching strategy at the Army War College. It was he who persuaded Ushijima to adopt the defensive jikyusen (war of attrition) strategy employed on Okinawa to bleed white the Americans, as opposed to General Cho’s preferred massed banzai charges. Yahara and Cho clashed often over tactics, but the general eventually relented and allowed Colonel Yahara to return to his former tactical doctrine of “retreat and defend.”

After the war, Yahara’s U.S. Army interrogation officer noted, “Quiet and unassuming, yet possessed of a keen mind and a fine discernment, Colonel Yahara is, from all reports, an eminently capable officer, described by some POWs as ‘the brain’ of the 32nd Army.”

In the spring of 1945, Admiral Chester W. Nimitz, commander of Pacific Ocean Area Forces, had an immense arsenal at his disposal. Practically every plane, ship, submarine, soldier, and Marine in the Pacific was made available for Iceberg.

Beneath Nimitz was the huge joint Army-Navy Central Pacific Task Forces headed by U.S. Navy Vice Admiral Raymond A. Spruance, commander of the Fifth Fleet. There were numerous subordinate commands, including Task Force 50, a naval covering force, and special groups that were also under Spruance’s personal command. Task Force 51, a joint expeditionary force, was under the operational control of Vice Admiral Richmond K. Turner, commander of Amphibious Forces Pacific Fleet. Task Force 57 included British warships. Air operations were under the command of Vice Admiral G.D. Murray, and Vice Admiral Charles A. Lockwood was in charge of American submarine forces.