Commentary / Japan

If only Iwo Jima had been captured sooner

The Battle of Iwo Jima began 75 years ago today, on Feb. 19, 1945. The capture of the 21 square kilometer island was expected to “only” take a few days, but it ended up requiring five weeks due to the elaborate dug-in defenses (hidden artillery, mortars, land mines, tunnels and bunkers) that Lt. Gen. Tadamichi Kuribayashi had in place, the ability of the Imperial Japanese Army and Navy forces to persevere under unimaginably harsh conditions, and the U.S. Navy’s unfortunately short and eventually ineffective pre-invasion bombardment.

Although there was a heated public discussion in the United States after the battle began over the merits of taking Iwo Jima in proportion to the extremely high casualties (eventually, more than 6,800 U.S. personnel were killed, and nearly approximately 19,000 wounded), it is clear now (as it was then) that the joint efforts, led by the U.S. Marine Corps, to take the island was a decisive game-changer.

Specifically, the reasons for taking Iwo Jima were numerous and can be summarized as follows:

First, American “very long range” bombers (B-29s) could fly closer to Japan without being detected.

Second, bombers could avoid flying near Iwo and thus would require less fuel and could carry more tonnage.

Third, Iwo Jima would serve as a base for fighter planes (primarily the long-range North American P-51 Mustang) that could escort the bombers to and from mainland Japan.

Fourth, Iwo Jima would provide an important midway point for damaged bombers and other aircraft to land and get repaired.

Fifth, search and rescue operations could be done from Iwo Jima more easily than from the Marianas for pilots and crews of bombers and other planes that crashed in the sea.

Sixth, the capture of the runways on Iwo would stop it from serving as a base from which Japanese aircraft would could harass U.S. operations and bases in the central Pacific.

Seventh, the capture of Iwo Jima, Japanese territory — indeed, under the jurisdiction of Tokyo — would send an important psychological blow to Japan that the end was near.

What was not publicly known then, however, was that there had been an internal tactical debate that would have future strategic implications about the course of the war and the postwar. Namely, shortly after the beginning of the campaign to seize Saipan in June 1944, planners in the Joint War Planning Committee (JWPC) under the Joint Chiefs of Staff (JCS) turned their attention to altering the plan to retake Guam and instead pursue the immediate occupation of Iwo Jima.

These planners had learned through intelligence that Iwo Jima’s defenses were at this point, early on, poorly organized. With the Japanese fleet heavily damaged in the largest carrier battle in history between the U.S. and Japanese navies in the Philippine Sea on June 19-20 in what became known as the Marianas Turkey Shoot, planners thought Iwo Jima could be seized quickly and made into an air base for two bomber groups of B-24 Liberators and an equal number of fighter groups. Guam could then be reconquered.

Unfortunately, the leadership of the JWPC disagreed with the proposal, believing that Iwo Jima would be logistically difficult to maintain. The leadership also noted that changes in the plans would throw “months of planning out of sequence” and doubted that “plans and current operations could be altered in time to take advantage of it.”

Navy photo reconnaissance and other intelligence turned out to be correct — Iwo Jima and the rest of the Bonin Islands remained far from prepared. The breaching of the outer perimeter to the “Inner Vital Defense Zone” in the summer of 1944 had simply been too fast and expectations by the Japanese leadership of the fleet to survive too high. Japanese officers later said the U.S. could have easily taken Iwo Jima at this point.

Yoshitaka Horie, who served on Kuribayashi’s staff, whose memoirs I translated and published a decade ago, stated after the war, “The fact that Iwo Jima was not invaded in the summer of 1944 surprised us all. The island was barely able to defend itself! A fraction of the force which took Saipan could have stormed Iwo’s beaches and crushed the token resistance which our skeleton forces then on the island could have mustered. … Yet no invasion came. We considered this turn of events as nothing less than a miracle.”

Unfortunately for U.S. forces, waiting another eight months to invade Iwo Jima as part of “Operation Detachment” allowed Kuribayashi the time to make Iwo Jima into one of the most heavily fortified islands ever — some 21,000 Japanese personnel were on the island by this point versus 5,000 the previous spring.

Charles W. Tatum, who was in the first landing force on Iwo Jima and co-edited Horie’s book with me, wrote critically later that “indecision [of the JCS] in not targeting Iwo Jima sooner was a tragic flaw which would cost thousands of American lives in February-March 1945, when the island was finally invaded 30 days behind the original JCS timetable.”

This may be wishful thinking, but had the capture of Iwo Jima — which was historically Japanese territory unlike the other Pacific Islands lost in the battles to date — taken place in the summer of 1944 as the Hideki Tojo Cabinet was collapsing, the war probably would have taken a different course, perhaps making unnecessary the Battle of Okinawa (which killed approximately 100,000 civilians and an equal number of those in uniform); the fire-bombings of Tokyo and many dozens of cities in mainland Japan repeatedly, which killed more than 200,000 people; the dropping of two atomic bombs, which further killed more than 200,000 civilians; and the Soviet Union’s August 1945 entry into the war, which led to the illegal seizure of the islands off the coast of Hokkaido.

In this sense, it was not only the forces of both sides of the battle who should be remembered at this time, but also the above victims as well.

Robert D. Eldridge, who served as the political adviser to the U.S. Marine Corps in Japan from 2009-2015, has made frequent visits to Iwo Jima for research and as a participant and interpreter for the bilateral Reunion of Honor Ceremony.

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