Operations which didn’t happen (part 1): British participation in the invasion of Japan, 1945

Had the atomic bombs not been dropped on Hiroshima and Nagasaki, resulting in the unconditional surrender of Japan, the military landscape in late 1945 and early 1946 would have looked very different. In what would have been the largest amphibious operation in history, coming under the overall umbrella of a plan known as Operation Downfall, Allied forces had intended to invade the home islands of Japan.

World War II poster - The War Against Japan.
World War II poster – The War Against Japan. Catalogue ref: INF13-213 (46)

Made up of two parts, the initial assault, Operation Olympic, was set to begin in November 1945, and would see the capture of the island of Kyūshū in the south, using the recently captured island of Okinawa as a staging area. Forces were to be made up exclusively of units from the United States.

The second part of Downfall, Operation Coronet, would begin in early 1946, and involved the invasion of Honshu, close to the Japanese capital of Tokyo. Though the Allies planned to use predominately troops from the US, a British Commonwealth Force was in the process of being assembled in August 1945 to take part, and records at The National Archives shed some light on the decision making process and rationale behind British and Commonwealth participation.

In early July 1945, the British Chiefs of Staff had prepared a memorandum which gave details relating to the policy of inducing the unconditional surrender of Japan. This would be done by ‘lowering the Japanese ability and will to resist’ using sea and air blockades, and ‘invading and seizing objectives in the industrial heart of Japan’ (DEFE 2/165).

As well as Operation Downfall, British forces had been preparing for the liberation of the Malay Peninsula and recapture of Singapore. These operations were to be known as Operation Zipper and Mailfist, and utilise a significant proportion of the British, Imperial, and Commonwealth troops.

However, important political considerations had to be taken into account. By early August 1945, Ernest Bevin, the British Foreign Secretary, warned that a lack of British participation in the invasion of mainland Japan would risk an accusation in the future from the US and countries in the Far East that Britain had not pulled its weight, and also that it was important to ‘re-establish our position in the eyes of the Far Eastern peoples’. The Prime Minister of Australia, Ben Chifley, sent a telegram to the British Prime Minister, Clement Attlee, stating that Australian participation was of ‘vital importance to [the] future of Australia and her status at [the] peace table’ (DEFE 2/165).

The British authorities made it clear that they wished to have a presence and the US conceded to its view. The whole operation was to be run by General Douglas MacArthur, Supreme Commander, Southwest Pacific Area, and Admiral Chester Nimitz, the Commander-in-Chief of the US Pacific Fleet, and the former sent a list of proposals to be agreed upon for the British to participate. It stated that there would be no possibility of British autonomy in the operation, meaning essentially that its forces would have to come under US command. The divisions earmarked would simply be replacing American divisions already allocated for service during Coronet.

General MacArthur's plan for Operation Coronet.
General MacArthur’s plan for Operation Coronet. Catalogue ref: DEFE 2 165

MacArthur also stipulated that British Empire participation should be limited to a Corps of three divisions: one British, one Canadian, and one Australian. Britain had initially proposed to send an Indian division, but this was rejected on the grounds of administration and because of a possible language barrier. However, the records show that there was a feeling among senior British officials that the rejection was based ‘entirely on political reasons obtaining in America’ (CAB 79/37/10).

One British, Canadian, and Australian division was approved, with a smaller New Zealand contingent also earmarked for service, in a force that would eventually total 55,000. The Australian division would train and embark from Borneo, while the British and Canadian contingent were to be transported to the United States for training on 1 October 1945. The prevailing feeling was that ‘the passage of a British Division through the United States will have a good effect on United States public opinion’. Once in North America, the divisions would be re-quipped with American weapons in order to simplify supply lines once the operation had begun. British authorities had insisted, however, that the British division, at least, should be permitted to retain its own uniform.

List of the shipping requirements for the number of troops for the invasion of Japan in 1945-6.
Shipping requirements for number of troops 1945-6. Catalogue ref: DEFE 2 165

After some debate, the British 3rd Division was earmarked for service. This division had fought during the Battle of France, had landed on Sword Beach on D-Day, fought through the Battle of Caen, Operations Goodwood and Charnwood, and participated in operations across north-west Europe until VE Day. It was chosen because it was already a fully trained division and, officials admitted, ‘a small proportion may be left who took part in the assault on Normandy in June 1944’ (WO 193/825). Members were to be given 28 days leave before their date of embarkation and would realistically have spent the next six months in North America, before making its way to the Pacific.

Orders to that effect were to be issued to British Commonwealth land force Commanders of the ‘Coronet Force’ on 10 August 1945, a day after the second atomic bomb had been dropped on Nagasaki, and the Soviet Union’s declaration of war on Japan. By 15 August, Japan had surrendered, and this was formalised on 2 September when MacArthur accepted on behalf of the Allies on the USS Missouri in Tokyo Bay. British and Commonwealth forces, of course, were no longer required for the task they had begun to prepare for, but it is certainly interesting to think about what was being put in place had the atomic bombs not been dropped.

Related blogs:

The atomic bombing of Hiroshima


  1. Richard Williams says:

    Really disappointing the Royal Navy and Royal Air Force commitments to Operational Olympic are wrongly ignored in this piece.

  2. Richard says:

    Interesting indeed and a further part/parts is/are eagerly anticipated – hopefully concerning the proposed deployment of ‘Tiger Force – the RAF air contingent of Operation DOWNFALL.

  3. Barry says:

    At the time the atomic bombs were dropped on Japan my father was at Trincomalee in Ceylon (now Sri Lanka). He was in the navy with landing craft and he told me that it was planned to do a landing against the Japanese in Malaya at Rangoon, similar to the D-Day landings. I’ve never seen any reference to this operation anywhere and wonder if it was correct.

  4. James Sykes says:

    Both my father and my wife’s father were part of Tiger Force and were heading for Okinawa as far as they both knew. My father contingent were held back when the first bomb was dropped by being diverted to Hawaii.
    They were in different squadrons and my father was in that part of the force eventually redirected to Hong Kong for the clear-up there; whereas my father-in-law ended up in Japan and spent six weeks in Hiroshima before being sent to India. Was sending British forces to Hiroshima part of some more sinister experiment?

  5. terence carman says:

    Australian/NZ division would have meant ANZAC forces. Justly so. McArthur wanted to ensure that the remaining Crown forces had no leading influence in the forthcoming invasion. No surprise there. By this stage of WW2 the US was the premier leader of allied countries, the military might of the US at the time was so evident, that Soviet Russia did not challenge from their position in Europe. The Brits knew even after their heroic stand against Nazi Germany earlier in the war, that their world leadership in many areas such as naval size and ability was waning against the US. It was money and industrial might of the US. Politically the Brits would have had to be part of the invasion, US military might kept the Japanese out of Australia, then a nation of under 6 million people? Predominantly of British/Gallic decent. Britain had been unable to defend Australia, a shocking revelation to the Australians at the time. Hence going forward the reliance of Australia on the US. Australia now is about to spend billions of dollars on re-modernizing its Defence Forces, because of the growing current threat from China. It could also be said, that the present President of the US has indeed placed pressure on the Australian Government to take responsibility for its share in defending its part of the world. The same can now be said of those countries of Europe that are part of NATO.

  6. Joe Hawkins says:

    I was happy to see that the Brits,Aussies and Canadians would have been involved to assisting the US in the assault on Japan. It appears General MacArthur was in control
    of implementing the operation. My Dad’s cousin won the Distinguished Flying Cross for operations on the battle on Iwo Jima. We were great and still are great allies.

  7. Philip Virgo says:

    I assume that the US opposition to an India Army Division was a mix of racism and anti-imperialism. Is there anything in the archives on plans to liberate/protect the prisoners of war. My father was one of those who had already dug his own grave for execution should any of these plans have been put into effect. They had been “visited” by a couple of “special forces” troops who “came out of the jungle” to “see how they were”. I will not be celebrating VJ Day because it was another ten days before they were reasonably confident that they were not going be slaughtered. When they were first captured a Japanese Officer (educated at Oxford) had formally apologised for how they would treated and asked that when the war was over, and the Japanese Empire had been destroyed by the Americans and Russian, those who survived would hold their guards to account against Japanese codes of honour, which he explained.

  8. Adrian Villanueva (Lt MRNVR Singapore Division) says:

    Thank God that the War in the Far East ended with the A-Bombs dropped in Hiroshima & Nagasaki. It would be a bloody battle if Japan did not surrender if the bombs were not dropped. The Japanese Generals were willing to sacrifice the lives of not only their troops but also their local population. It would have caused the lost of thousands of British, Commonwealth & US Troops that planned to invade Japan. As we commemorate 75th Anniversary VJ Day on 15 August 2020, we will remember those who died in Service during WW2 (Far East). Lest we Forget.

  9. Warwick says:

    It is suggested here that one of the reasons (the most important ?) for British involvement in the invasion of Japan was to ‘re-establish our position in the eyes of the Far Eastern peoples’. In other words, to facilitate the re-establishment of empire and hegemony over a substantial part of SE Asia. Surely this was wishful thinking given the humiliating defeat of British forces in Malaya and Singapore in 1942 ? As it turned out, the return of all three European empires – Britain, France, and Holland – were vigorously resisted by their former colonial subjects, and it wasn’t long before the continuing US presence in the Phillipines was also resisted by the local people.

    It’s great that these archives are being opened up, but please let’s use them to learn something useful from them. Let’s not use them just to wallow in imagined past glories. Although it was important that Japan be defeated, let’s not forget that the US, Britain, and Commonwealth countries only got involved in resisting Japanese aggression when they themselves were attacked; they were happy to sit back and ignore it while China was under attack throughout the period 1931-1942.

  10. c j clayton says:

    I am so happy that the bomb was dropped ,it meant my father came back from Burma ,he could so easily not have if the war had continued and Vinegar Joe had had his bigoted way with the U K troops .
    A pity the P O W s did not get the consideration and some recompense they deserved.

  11. J Boulter says:

    The RN had been in action for a long time , my father’s ship was with others part of a large fleet . The brought up resupply ships once , a couple of times. .

  12. Catherine Shirley says:

    I wholeheartedly agree with C J Clayton’s statement – plus the POWs were just left without support after being ‘sneaked’ back into the UK. No health checks after such an experience was disgraceful. A family friend was an ex POW and suffered an intestinal problem which was finally diagnosed in the 1960s. He never fully recovered his health. It certainly affected his mental health. He always felt that the UK government were ashamed and just wanted to cover up the ineptitude of military leadership.

  13. Warwick says:

    ‘It was important to “re-establish our position in the eyes of the Far Eastern peoples”‘ says it all. After taking a thrashing in SE Asia, all of the European based empires – British, Dutch and French – were hell-bent on re-establishing their hegemony over the people and resources in that part of the world In each case they failed because the local people had other ideas; they weren’t about to have the Japanese imperial yoke removed only to have the old European ones restored.

  14. Pauline says:

    My father, in RAF Bomber Command, was to be deployed in Tiger Force, going out to the Far East. He designed a tiger emblem to be used as a badge. I have his original art work.
    This is from some information on Wikipedia aboutTiger Force
    Tiger Force, also known as the Very Long Range Bomber Force, was the name given to a World War II British Commonwealth long-range heavy bomber force, formed in 1945, from squadrons serving with RAF Bomber Command in Europe, for proposed use against targets in Japan. The unit was scheduled to be deployed to Okinawa in the Pacific theatre in the lead-up to the Allies’ proposed invasion of Japan. The unit was disbanded after the bombings of Hiroshima and Nagasaki and the Soviet invasion of Manchuria ended the war.

  15. Shelagh Smethurst says:

    My father was very pleased that the Americans dropped the bombs. He had been captured at the fall of Singapore and wouldn’t have survived much longer.

  16. Warwick Dilley says:

    Thank you for an interesting blog. I noted that one of the reasons why Bevin wanted British forces involved was to ‘re-establish our position in the eyes of the Far Eastern peoples’. Presumably, this was so as to facilitate the recovery of the colonies that had been occupied by Japanese forces and the re-establishment of colonial administrations. I wonder to what extent the British government of the time foresaw, and understood, the rise of independence and nationalist sentiments that would occur in those countries (and in the former French and Dutch colonial territories) once the Japanese occupation had collapsed. Are their documents available that would show what preparations were being made for re-establishing civil administration in these colonies ?

  17. Adrian Villanueva says:

    It would be a terrible lost of lives if the attacks had been carried out by the British & Commonwealth Forces trying to retake Singapore & Malaya from the Japanese forces who were willing to sacrifice their lives for their Emperor & the greater glory of Imperial Japan. Same situation would have happened if the American & Allied Forces tried to retake Japan. The Japanese Generals were determined to fight to the end with NO surrender. The A Bombs dropped in Hiroshima & Nagasaki put an abrupt stop to the War. VJ Day 75th Anniversary was celebrated on 15 August 2020 in Singapore, UK and throughout the World. Lest we forget our soldiers, sailors & airmen of the British & Commonwealth Forces, including my predecessor unit the “Straits Settlements/Malayan Royal Naval Volunteer Reserve (Singapore Division)”. They died So that we may live. Lt Adrian Villanueva MRNVR (Singapore Division) 1960s

  18. Warwick says:

    I’ve tried several times to post on the political element of these plans but to date I’ve not been successful. The political element is explicitly raised in the blog in the reference to Bevin’s warnings about the post-war political dangers of not being involved. Further, the blog says that ‘the divisions earmarked would simply be replacing American divisions already allocated for service during Coronet’ which implies that the proposed British/Canadian/Australian force was not actually adding to the forces need for the invasion. The point that I’m making is that these plans for British involvement seem to have been more about post-war political objectives rather than immediate military objectives.

  19. Peter Fuller says:

    The invasion of Rangoon in Burma, named Operation Dracula, was intended for the 2nd May 1945, so somewhat earlier than any plans for the invasion of Japan. On the 1st May 1945 a Mosquito bomber of 110 Squadron, flown by W/Cdr Arthur E. Saunder OBE with navigator F/Lt James Bryden Stephen, went from RAF Joari on reconnaissance to Myingyan airfield, Burma. Flying low over Rangoon, they noticed a message painted on the roof of the PoW camp which read “Japs gone. Extract digit” They found Myingyan airfield abandoned and landed to investigate. Unfortunately they crippled the plane on landing, hitting one of the many bomb craters in the runway. They made their way to the PoW camp and were told that the Japanese had left the city. They took photographs and then left so that they could tell the navy not to shell Rangoon as had been planned for the next day. They went to the docks from where they took a boat to the mouth of the river where they met a naval flotilla.

    At the time of the Japanese surrender in August plans were well advanced for the invasion of Malaya with troops, ships, landing craft and air forces already being in position. Operation Zipper was the British plan to capture either Port Swettenham or Port Dickson, Malaya, as staging areas for the recapture of Singapore in Operation Mailfist. However, due to the Japanese surrender, it was never fully executed. Some of the proposed landings on Penang went ahead as planned to probe Japanese intentions, but encountered no resistance.

  20. clayton says:

    “c j clayton
    Fri 14 Aug 2020 at 4:37 am
    I am so happy that the bomb was dropped ,it meant my father came back from Burma ,he could so easily not have if the war had continued and Vinegar Joe had had his bigoted way with the U K troops”

    stillwell had been gone from SEA for 10 months, by August ’45.

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