The Battle of Okinawa — 65 years ago today

Okinawa 65 Years ago today —

May 14, 1945

On Okinawa, 20 American Marines reach the summit of Sugar Loaf Hill. This is the first of several assaults that reach and be pushed off Sugar Loaf before it is finally captured.

The airfield at Yonabaru is captured.


This is the belated beginning of an occasional 65th anniversary commemorative series on the of the Battle of Okinawa.

Background to this point:

Sixty-five years ago, on 1 April 1945, American forces launched Operation Iceberg, the invasion of Okinawa. Two corps of the US 10th Army (General Buckner) land in the area of Hagushi, in the southwest of the island. The troops landed are from US 3rd Marine Amphibious Corps (Gen. Geiger USMC) with US 6th and 1st Marine Divisions, on the left or northern flank, and 24th Corps (Gen Hodge US Army) with US 7th and 96th Infantry Divisions, on the right or southern flank.

This assault will face the 32nd Japanese Army in a World War One style slugfest on the southern part of 70 miles long by three-to-10 miles wide island that will see over 90% of the Japanese Army garrison killed in combat with the American 10th Army.

The US Navy will see more ships sunk and men killed in this campaign by Kamikaze attacks than any other in World War II.

01 thru 07 April 1945 — The Ground Campaign Mobile Phase

The Japanese 32nd Army’s commander Lieutenant General Mitsuru Ushijima chooses not to defense the beaches of Okinawa due to ground forces being stripped and sent to defend the Philippines. Northern Okinawa is quickly occupied by Marines of the 3rd MAC while troops of the Army’s 24th Corps in the south run into the Japanese Shuri line.

08 April thru 03 May 1945 — Finding and Grinding the Shuri Line

Grinding WW1 style attrition warfare starts at the 32nd Army’s Shuri line defenses. US infantry battalion frontages are no more than 600 yards wide in the face of Japanese Army cave fortifications. Fighting there sees US Army’s 27th and 96th Divisions burnt out taking Shuri’s outer defensive Ring and weathering a six infantry battalion strong Japanese night-time counter-attack on 12 April 1945. They are replaced in combat by US 1st Marine and 77th Army Divisions.

04 thru 08 May 1945 — 32nd Army’s Banzai Counter-attack!

The Japanese 32nd Army counter attacks from the Shuri line. US ground forces face the largest Japanese artillery barrage of the Pacific War. The Japanese attack burns out in the face of American air, artillery and naval gun firepower.

08 thru 13 May 1945 — Attrition in the Mud!

Torrential rains arrive at Okinawa on May 8th, denying the attacking American infantry the use of armored flame thrower tanks and much artillery support due to deep pools of mud bogging tanks and resupply trucks. The 7th Infantry Division is pulled off the line to rest.

End Notes:

I used and the US Army’s official history by Roy E. Appleman here OKINAWA: THE LAST BATTLE for information in this post.

I plan future posts of some of the daily events and an overview of the naval campaign.

Many other internet resources on the Okinawa campaign will be used and posted.

11 thoughts on “The Battle of Okinawa — 65 years ago today”

  1. My father fought at Okinawa as a rifle platoon lieutenant in the 96th Division. My recollection is that he was one of four infantry lieutenants in the division who survived its entire time in the line without becoming a casualty, and that he took over a platoon just before it went into the line, as a replacement for the existing lieutenant who broke his leg falling out of the back of a truck while asleep.

  2. Trent thank you for remembering this anniversary.

    I read Eugene B. Sledge’s memoir With the Old Breed at Pelelieu and Okinowa and consider that one of the best books about the war I have read, and I have read a lot of them. I am currently reading, in bits and pieces, Max Hastings’ Retribution — but have not gotten to Okinowa yet. Still in the Phillipines, where things are not going as the Americans had planned. Okinowa is a few pages ahead yet.

    I look forward to your further posts on this horrendous battle.

  3. Thanks Dan, Tom, Lex,

    The US Army has made many of the original Okinawa operational documents of the US Army, US Navy and USMC are available on-line at it’s Combined Arms Research Library digital archive.

    The following is clipped from a PDF document there:

    Tenth Army: Action report: Ryukyus: 26 March to 30 June 1945. Volume I

    Page 7-V-1

    Total battle casualties of the Tenth Army, from 26 March to 30 June, were 38,976.

    Army units suffered 4,288 killed, 17,558 wounded, 91 missing, Marine units lost 2,744 killed, 13,523 wounded, 90 missing.

    Casualties by divisions were-
    3,252 for the 27th Inf Div,
    6,004 for the 7th Inf Div,
    5,026 for the 77th Inf Div,
    7,252 for the 96th Inf Div,
    94 for the 2d Mar Div,
    7,962 for the 1st mar Div, and
    8,242 for the 6th Mar Div,

    The heaviest losses in the Tenth Army occurred during the period 19-22 April when the XXIV Corps suffered 2,851 casualties– and from 10 to 19 May when the III Phib and XXIV Corps combined total was 6,470.

    Page 7-V-2

    The Japanese army suffered irreplaceable losses- The 62d, the 24th Div, and the 44th Independent Mixed Brigade were destroyed completely. 107,539 enemy soldiers were known to have been killed and 7,401 were taken prisoner. Countless others undoubtedly lie buried in the hundreds of caves that were sealed during the battle,. All of the enemy’s supplies and equipment were either destroyed or captured. . A large-and important contribution to the destruction of the Japanese armed forces was made when this beacon in the Japanese home-waters was ‘snuffed out.

  4. Okinawa led directly to the nuking of Japan.

    The island fighting was brutal beyond belief and Okinawa was often the worse. Military planners presumed that Okinawa defenses would be the template for Japanese defenses on the mainland and that the fighting on the mainland would be every bit as brutal except on a vastly larger scale.

    The island fighting in general led to increased support for massive bombing raids, carrier raids, submarine blockade against the mainland in attempt to bring about a surrender without an invasion. The use of atomic weapons was just last in that escalation.

    There was never any possibility that American planners would have forgone using atomic weapons if the other option was fighting another Okinawa a hundred times over.

    Ironically, the Japanese strategy was based on inflicting such high causalities on Americans that we would give up rather than invade. Instead, it just drove us to whip out the big guns.

  5. Shannon,

    The Japanese wanted to fight to death for honor.

    America was very much willing to kill them all in order to win, with a few American deaths as possible.

    Had the Japanese military coup against Hirohito’s surrender succeeded, we were going to gas the Japanese like bugs. Whatever the US Navy at the time or later academics thought or didn’t think.

    The reason was simple. The Japanese Military was planning on thoroughly dehumanizing itself in Western Eyes to get just the fight it wanted.

    Tennozan: The Battle of Okinawa and the Atomic Bomb by George Feifer, states at page 573:

    “After the fall of Okinawa, Field Marshal Count Hisaichi Terauchi issued an order directing his prison camp officers to kill all their captives the moment the enemy entered his southeast Asia theater. That would have been when those 200,000 British landed to retake Singapore, less than three weeks after the Japanese surrender. There was a real chance that Terauchi’s order would have been carried out, in case up to 400,000 people would have been massacred.”

    We knew about this due to MacArthur’s code breakers being able to read Japanese Army codes in real time by 1945.

    Those mass mass murders would have started in Sept 1945, when the British Amphibious Invasion of Malaya (Operation Zipper) kicked off and MacArthur’s planned but little written on invasion of Java went in.

    By the time of the Operation Olympic, the British would have been in the dead city of Singapore and the Eight Army would have over run the bodies of the white Dutch murdered by the Japanese in Batavia. The pictures of the bodies would have been daily fair for American newspapers.

    Picture the American outrage after Pearl Harbor, times 10.

    Then go read these articles: “Gassing Japan”, Norman Polmar and Thomas B. Allen, MHQ: the Quarterly Journal of Military History, vol 10 no 1 (Autumn 1997), pp 38-43, and The Most Deadly Plan, Norman Polmar and Thomas B. Allen, Proceeding of the US Naval Institute, January 1998 edition, pp 79-81.

    The US Army’s Chemical Warfare service had huge stores of chemical weapons in Australia and other South West Pacific Area bases.

    See: Chemical Warfare in Australia

    This is the “5-day supply” of chemical weapons academics like John Ellis van Courtland Moon cite as being “inadequate” in articles like this:

    “Project SPHINX: the Question of the Use of Gas in the Planned Invasion of Japan,” Journal of Strategic Studies 12 (September 1989): 303-323

    There were tens of thousands of tons of additional “retaliatory” chemical weapons being shipped as a part of Operation Olympic.

    The Chemical Warfare service did an extensive survey of Japanese chemical preparedness in 1945-46 as a part of the disarmament of the Imperial Japanese military.

    This is part of what it said, from page nine of :

    (4) In the home islands

    By the time an invasion of the home islands
    was imminent, production of toxic gases had
    been discontinued. The possible strategy of
    defense of the beaches against a hostile
    landing with gas was considered and rejected.

    Stocks on hand were too small for extensive
    operations, the Japanese Air Force had been
    reduced to impotence so that planes were no
    longer available to use it in the most effective
    way, and the few available planes were
    needed to carry HE for Kamikaze attacks
    against invasion ships and could not be spared
    to deliver gas attacks.

    As a final consideration, the extreme vulnerability
    of all Japanese cities had been demonstrated
    by the devastation wrought by
    incendiary bombs dropped by B-29 and carrier
    based planes over all parts of the home
    islands. Under such conditions, the Japanese
    fully recognized their helplessness and
    complete inability to withstand gas attacks,
    having almost no gas proof shelters, no
    protective clothing suitable for prolonged
    wear, and inadequate and inferior gas masks
    for the civilian population.

    The location and condition of captured toxic
    munitions indicated storage in normal supply ‘
    depots without special strategic significance.

    That was the Chemical warfare Service’s way of saying most Japanese chemical weapons, 200,000 artillery shells were located in Kyushu….


    While the majority of their bulk chemical stocks to fill those shells was located in Tokyo area depots on Honshu.

    When the American military’s preparatory air campaign rolled in and destroyed Japanese railways and choked off their coastal shipping with more sea mines. The Japanese military would have been unable to reply with the majority of their available CW artillery weapons.

    This would have left air delivered munitions, of which the most effective would be spray tanks on aircraft with mustard gas.

    All those spray tank armed Kamikaze would have had to do is fly into the beach head area and hit the dispense button. This is the strength of a real area effect, persistent, CW weapons.

    However, most of those spray tanks were in the Tokyo area for the IJA and in Yokohama and Sasebo areas for the Imperial Japanese Navy. They were not in Kyushu or Shikoku Imperial Japanese Army and Navy airfields

    It would have taken a week or more to put together a “significant;” CW aerial attack force, because the supply depots had been decentralized under B-29 attacks, and the Japanese aerial CW attacks would have pretty much the same range problems its Kyushu based planes had at Okinawa.

    In WW1, mustard gas used in the open disperses in 48 hours — sunlight and fresh air are still the best disinfectants — but it persisted in dark, moist, bomb proof under ground dug outs for up to a week after a major gas attack.

    We would have drenched the main Kyushu beaches with aircraft spray tank delivered mustard on every evening X minus seven days (X-Day being the D-Day for Operation Olympic) through X-3 before the X-day landings. And would have uses non-persistent phosgene gas on X-2 and X-1, after our bombardment task forces left each day. This would be done so the evening sea-to-land on-shore breezes would carry the gas inland, up the draws, and into the caves where the Japanese defenses were.

    Then on X-day we would have hit the beaches with 4.2 inch mortar gunboat delivered phosgene for the hour immediately prior to the first wave of the landings.

    Japanese gas masks would last about four hours in a contaminated environment without strenuous physical activity and only one hour with such activity, such as firing and reloading artillery or carrying heavy loads of supply.

    The majority of Japanese Southern Kyushu Beach fortifications would have fallen in a less than a day after the landings due to;
    1) Lack of gas proof shelters in their cave defenses for food and water,
    2) Inadequate decontamination means for their heavy weapons and ammunition, and
    3) No means to get horse or completely gas mask-less local civilian home guard porters through to forward fighting positions to supply replacement gas mask filters.

    We would have taken more casualties from our own gas and friendly gunfire than from the Japanese.

  6. I think the bomb was the only option that saved the POWs.

    In “Downfall,” the author discusses the bomb and the fact that Japan had an atomic bomb program, aided by the Germans. After the first bomb, the Japanese scientists told the Emperor that we could not have enough U 235 for another bomb and encouraged him to continue the fight. It was the second bomb that changed their advice. They now believed we could have many more bombs and it was time to quit.

    What they did not realize was that they were correct about U 235. We had no more. They did not anticipate the plutonium bomb, which was the second one dropped. That was the one that won the war and saved the POWs.

  7. Lex,

    I am planning too, but not in the context of posts on the Battle of Okinawa.

    Part of the reason for the series on Okinawa is that I have done a lot of reading and research on the decision to use the Atomic bomb versus invasion of Japan by Truman.

    Tom Holsinger gave me a copy of HELL TO PAY: Operation DOWNFALL and the Invasion
    of Japan, 1945-1947 by D. M. Giangreco for Christmas 2009. Giangreco’s book is from the military history community and supported the use of the A-bomb to end the war. I was looking forward to it because it was the first serious military history post the Norman Polmar and Thomas B. Allen articles on gassing Japan.

    However, when I read it, I found Giangreco essentially ignored the subject of gas.

    Add in a few of bothersome passages that I fact checked with wikipedia, Lone Sentry, and Hyperwar — with resulting EPIC FAIL with Giangreco’s descriptions of late WW2 American military technology and doctrine — that it became a minor obsession to look at on-line source material on the subject of invasion versus the A-bomb.

    The bottom line conclusion I came to is that this field of historical research lost dispassionate academic rigor in 1965. That is when the left-wing revisionist Diplomatic historians started making their case that the A-bomb was all a plot to start the Cold War with the Soviet Union.

    Post-Cold War Military Historians started using the same sorts of unprofessional methods of advocacy after the WW2 generation of military historians died off.

    As a result, anything post 1995 — the 50th anniversary of WW2 — and most everything between 1975 and 1995, is worthless because of the efforts required to vet the research for accuracy. (The only exception I have found has been Downfall: The End of the Imperial Japanese Empire by Richard B. Frank. He is a military historian.)

    Any A-bomb decision history written prior to 1975 — with or without rigor — lacks the Ultra/Magic code breaking dimension.

    The diplomatic and military historical academic communities on the subject of the A-Bomb decision were merely the gust front of the collapse of real dispassionate academic professionalism in favor of “tenure careerism” which hues to a party line of the chosen field over real research effort.

    And that is a crying shame as the massive post-Cold War declassification’s and posting on-line of the 1946 CWS investigative-intelligence on Japanese chemical warfare capabilities sheds a great deal of light on the last days of WW2.

  8. Trent, that sounds good. This is very important information. I recall reading that after LeMay had burned down every city, town and village in Japan, they were going to equip the B-29s with poison gas tanks and use 4 engine bombers to spray chemical weapons on Japan, crop-duster fashion. The picture that brought to mind, swarms of giant bombers coming in very, very low, and putting thousands of tons of gas on huge swathes of Japan, stuck with me strongly. I don’t recall where I saw it. But I agree absolutely that it is an aspect of the war planning that is virtually never talked about. I tell people who toss off the conventional wisdom about the evils of the atomic bombing, “if you think the A-bombs were evil, you should hear about what we were going to do to them if the bombs didn’t make them quit.”

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