Unconditional Surrender


Excerpt from HIROSHIMA NAGASAKI: The Real Story of the Atomic Bombings and Their Aftermath, by Paul Ham

Thomas Dunne Books, 2014


The Japanese were defeated but would they surrender? The question perplexed the White House, War and State Departments. Truman’s reiteration of the phrase ‘unconditional surrender’ had become a populist slogan and unsettled several prominent figures within his administration, who shared Churchill’s view that a softening of the terms might end the war sooner. The whole question of surrender hinged on whether or not to grant the Japanese their single, abiding request: the retention of the Emperor. Meeting that condition was utterly unacceptable to hardliners in the State Department and the American people. The moderates, however, advised sending a clear statement to Tokyo to the effect that Japan must surrender all her arms and territory, submit to American occupation and a war crimes trial; but could keep their Emperor as a powerless figurehead.

The moderates’ motives were honourable: to impose terms that were close to ‘unconditional’, in order to secure Japan’s capitulation, end the war and limit American casualties; uppermost in their minds were the deaths likely to accompany a ground invasion, if it went ahead. Chief among those calling for softer terms was Joseph Grew, the Under Secretary of State, who had been US ambassador to Japan in the decade before Pearl Harbor. Grew understood the Emperor’s place in the Japanese psyche as few in Washington did. A carefully phrased ultimatum that spared the Emperor’s destruction would, he believed, compel the Japanese to surrender at little cost to American honour, with a concomitant saving of many lives: ‘Surrender by Japan,’ he warned on 14 April, ‘would be highly unlikely regardless of military defeat, in the absence of a public undertaking by the President that unconditional surrender would not mean the elimination of the present dynasty …’ At various times, War Secretary Henry Stimson, Chief of Staff William Leahy, Assistant Secretary of War John McCloy, Navy chief James Forrestal and their colleagues similarly pressed Truman to ease the terms, to accommodate Hirohito. Leahy went further: he saw ‘no justification for an invasion of an already thoroughly defeated Japan’, and hoped instead that ‘a surrender could be arranged with terms acceptable to Japan’.

Surely this was naive, argued the opponents of granting Japan a ‘conditional surrender’. There was no guarantee that Japan would surrender, even with the gift of the Emperor: Tokyo would interpret any lenience as weakness and fight on. In any case, Truman had a political motive to insist on the harshest peace: most Americans agreed with him and felt no compunction to ease the terms of Japan’s defeat and humiliation after four years of some of the bloodiest battles the world had seen. From New York to Texas, they longed to exact the most terrible revenge on the country that had inflicted Pearl Harbor and Bataan. Polls consistently showed a large majority in favour of unconditional surrender. A third wished to see Hirohito hang; most supported his imprisonment as a war criminal. Nine times as many Americans wanted [the servicemen] to fight on – ‘until we have completely beaten her on the Japanese homeland’ – rather than accept any Japanese peace offer, according to a poll on 1 June 1945. Their governing motive was vengeance: so many husbands, sons and brothers were dead, wounded or captive. As often in war, the civilians in the rear were more zealous for blood than the soldiers at the frontline.

Yet the same emotional impulse – to save America’s sons – drove many Americans to seek ways of ending the war through what they saw as a harmless compromise: the Washington Post, for example, challenged the insistence on ‘unconditional surrender’ in a powerful editorial on 11 June 1945:

[The two words] remain … the perpetual trump card of the Japanese die-hards for their game of national suicide. Let us amend them; let us give Japan conditions, harsh conditions certainly, and conditions that will render her diplomatically and militarily impotent for generations. But let us somehow assure those Japanese who are ready to plead for peace that, even on our own terms, life and peace will be better than war and annihilation.

Support for more conciliatory terms came from  an  unlikely  quarter. The Joint Chiefs of Staff – whom none dared call defeatist – circulated a fresh interpretation of unconditional surrender: ‘If … the Japanese people, as well as their leaders, were persuaded both that absolute defeat was inevitable and that unconditional surrender did not imply national annihilation, surrender might follow fairly quickly.’ The Joint Chiefs had a sound military reason  for  retaining  the  Emperor: as  a tool to subdue the armed forces (at Potsdam they would insist, from a purely military viewpoint, the Emperor should remain in office to subdue fanatical elements of the Imperial Army outside Japan).

Truman listened and initially agreed with these arguments. He was ready to consider any alternative to hasten the surrender and avoid the massive losses of a land attack. Abandoning Roosevelt’s casually invoked ultimatum of unconditional surrender would not, however, appease a vengeful public or firebrand congressmen – such as Senator Richard Russell of Georgia – who were conspicuously not at the frontline. Any amendment had to be sold politically.


In June and early July the plan to invade Japan, codenamed Operation Downfall, occupied Washington’s top military minds. If it went ahead, history’s largest seaborne invasion would realise MacArthur’s conception of two successive thrusts: first, the amphibious assault on Kyushu, dubbed Operation Olympic, scheduled for 1 November 1945; then the massed attack on the Tokyo Plain – Operation Coronet – set for March 1946.

On Monday 18 June, four days after Hirohito’s official intervention and the day after Truman noted in his diary – ‘shall we invade or bomb and blockade?’ in the wake of the carnage of Okinawa – the President convened a critical meeting of the Joint Chiefs of Staff in an effort to find an answer. This was crunch time for the invasion plan. The decision of whether to proceed rested, of course, with Truman, not with the Joint Chiefs, the Pentagon or MacArthur (who expected to command Operation Downfall). Truman  had  little  regard  for  ‘Prima  Donna, Brass Hat, Five-Star MacArthur’, as he had told friends during a sail down the Potomac the previous day. ‘It is a great pity we have stuffed shirts like that in key positions.’ Shortening the war and saving American lives preoccupied Truman, not soothing MacArthur’s considerable ego.

At 3.30pm the masters of America’s military strategy filed into the White House: Admiral Ernest King – clever, arrogant and ‘perhaps the most disliked Allied leader of World War II’ – who saw invasion as a contingency if the naval blockade failed; General George Marshall - honourable, self-disciplined, incorruptible – who advocated a massive, concentrated land invasion while exploring with War Secretary Stimson a workable surrender formula; Admiral William Leahy, Truman’s Chief of Staff, who thought strategic bombing of civilians was ‘barbarism not worthy of Christian man’ and that the naval blockade alone would defeat Japan – in the latter view, he had the support of Admiral Chester Nimitz, Commander in Chief of the Pacific Fleet. Lieutenant General Ira Eaker represented General Hap Arnold, the gruff, hard-driven chief of US Army Air Forces who shared LeMay’s absolute faith in strategic bombing – despite its failure in Germany – as an alternative to invasion. In attendance too were department chiefs Henry Stimson (War), James Forrestal (Navy) and John McCloy, the Assistant Secretary of War.

All were aware of S-1;  all  knew  of  the  atomic  test  planned  for 16 July; all were attuned to the hope that, if successful, the bomb – or the threat of it – might hasten the end of the war and remove America’s reliance on Russia. None entered the meeting disposed to mention this on the record; the elephant in the room remained a state secret officially aired in Target and Interim Committee meetings. The bomb’s absence from the minutes, however, did not mean it was not discussed.

Truman called on Marshall, as the senior soldier, to begin. The general outlined the forces and strategies being prepared for the invasion. The plan earmarked 1 November 1945 for the Kyushu landing (as MacArthur had proposed). The circumstances, he said, were similar to those that applied before D-day.  By November, Marshall added, American sea and/or air power will have:

• ‘cut or choked off entirely Japanese shipping south of Korea’;
• ‘smashed practically every industrial target worth hitting’ and ‘huge areas in Jap cities’;
• rendered the Japanese Navy, ‘if any still exists’, completely powerless;
• ‘cut Jap reinforcement capabilities from the mainland to negligible proportions’.

The weather and the helplessness of the enemy’s homeland defences further recommended a November invasion, Marshall said. ‘The decisive blow’, however, may well be ‘the entry or threat of entry of Russia into the war’ – Russia’s invasion of Japanese-occupied Manchuria, the ‘decisive action leveraging [Japan] into capitulation’.

Marshall turned to the likely losses, which aroused intense discussion – most of it inconclusive and hypothetical. The Pentagon estimated that American casualties – dead, missing and wounded – during the first 30 days of an invasion ‘should not exceed the price we have paid for Luzon’, where 31,000 were killed, wounded or missing (compared with 42,000 American casualties within a month of the Normandy landings). Several caveats qualified this relatively low body count: the invasion of Kyushu would take longer than 90 days, and the figures did not include naval losses, which had been extremely heavy at Okinawa. In any case, Marshall insisted ‘it was wrong to give any estimate in number’. The meeting fixed on 31,000 – a far cry from Marshall’s later estimate of 500,000 battle casualties, which Truman claims the general gave him after the war, and which has bedevilled debate ever since.

Marshall and King concurred that invasion was the ‘only course’ available: only ground troops could finish off the Japanese Empire and force an unconditional surrender. There must be no delay, King said; winter would not wait. ‘We should do Kyushu now,’ he urged (his sudden enthusiasm for the attack on Japan marked a departure from his earlier proposal to invade Japanese-occupied China). ‘Once started, however,’ King remarked, with words Truman dearly wanted to hear, ‘[the operation] can always be stopped, if desired.’

A dissenting voice was Leahy, who, at Truman’s invitation, questioned the surprisingly small casualty estimates, citing America’s 35 per cent casualty rate in Okinawa. In what numbers were we likely to invade Japan, he asked; ‘766,700’ US troops were projected, Marshall replied. They would face about eight Japanese divisions or, at most, 350,000 troops and, of course, a deeply hostile people. The dreadful mental arithmetic rattled the room: that left 270,000 Americans dead or wounded. King protested, however, that Kyushu was very different from Okinawa, and raised the likely casualties to ‘somewhere between Luzon … and Okinawa’ – or about 36,000 dead, wounded or missing. In this instance, King’s arithmetic was almost as dubious as his geography – Kyushu is a mountainous land riven with caves and hilly redoubts, rather like Okinawa.

So the invasion would be ‘another  Okinawa  closer  to  Japan?’ Truman grimly asked. The chiefs nodded. And the  Kyushu  landing  – was it ‘the best solution under the circumstances?’ the President wondered. ‘It  is,’ the  Chiefs  replied.

Unpersuaded, Truman asked for Stimson’s view. Would not the invasion of Japan by white men have the effect of uniting the Japanese people, he asked, interrupting the War Secretary, who had been regaling the meeting with dubious ideas about a ‘large submerged class’ of Japanese insurgents. Stimson agreed: yes, the Japanese would ‘fight and fight’ if ‘white men’ invaded their country.

His opposition to an invasion deepening, the President examined another card in his hand: the forthcoming Potsdam Conference, and how to get from Russia ‘all the assistance in the war that was possible’. This jolted the Joint Chiefs, who were forced to confront the military reality of ‘unconditional surrender’ – hitherto a political and diplomatic notion: it would mean a war in which the Soviets shared operations and, of course, the spoils. Were the Russians needed at all, several wondered. Silence. King spoke: the Soviets were ‘not indispensable’ and ‘we should not beg them to come in’. His view echoed the feelings in the room.

Leahy then broke ranks and directly challenged the ‘unconditional surrender’ formula: it would make the Japanese fight harder, he insisted. He did not think its imposition ‘at all necessary’. Truman appeared to agree, at least in part, suggesting that the definition of ‘surrender’ had not yet been fixed.

Clearly, for Truman, the invasion plan was fading rapidly from the list of possible alternatives. He authorised the continued planning of the operation, but did not, and would never, approve its execution. The collapse of the Japanese economy, the total sea blockade and ongoing air raids had ‘already created the conditions in which invasion would probably be unnecessary’. Indeed, Truman had convened the meeting precisely because he hoped to prevent ‘an Okinawa from one end of Japan to another’. If the invasion of Kyushu and later Honshu was the ‘best solution’ of ‘all possible alternative plans’, demons of doubt lingered between the lines of the President’s reluctant imprimatur.

In the days following, estimates of dramatically higher casualties further doomed the invasion plan. Nimitz, King and MacArthur all warned of a greater number of dead and missing than presented at the 18 June  meeting. Even MacArthur  ratcheted up  his modest  estimate, to 50,800 casualties in the first 30 days. No one could provide accurate projections, of course, and Truman never received a clear or unanimous calculation of likely losses, as King later said. Since the war, estimates of 500,000 to one million casualties have been crudely cited to justify the use of the atomic bomb – a classic case of justifying past actions using later information which was not applied at the time. At the time, nobody in a position of influence officially projected such astronomical numbers. The bomb, in any case, would not ‘save’ these hypothetical lists  of  dead  and  wounded:  in  late  June  and  early  July  Operation   Downfall lost the support of Truman and the Joint Chiefs not because the atomic bomb offered an alternative, but because the invasion plan was seen as too costly and, given Japan’s military and economic defeat, ultimately unnecessary – regardless of the success or failure of the atomic test.

The meeting drew to a close. But as the Joint Chiefs gathered up their papers, McCloy, thus far a quiet observer of the proceedings, spoke. A clever, thoughtful man, the Assistant Secretary of War was not afraid to express himself firmly. Only the day before he had urged Truman to drop the phrase, ‘unconditional surrender’. For months McCloy had shadowed the issue as the ‘leading oarsman’ in Washington opposing the policy: ‘I feel,’ he noted in late May, ‘that Japan is struggling to find a way out of the horrible mess she has got herself into … I wonder whether we can’t accomplish everything we want to accomplish without the use of that term.’

He now found himself sitting among ‘Joint Chiefs of Staff and security and Presidents [sic] and Secretaries of War’, contemplating the weapon nobody dared name. As they prepared to leave, Truman turned to McCloy and said, ‘Nobody leaves this room until he’s been heard from.’ McCloy glanced at Stimson, who nodded. McCloy’s words do  not  appear  in  the  official  minutes, but  he  reprised  the discussion in his memoir, and others present later verified his account: The bomb offered a ‘political solution’, McCloy said, that would avoid the need for invasion.

A hush ensued. McCloy continued: ‘We should tell the Japanese that we have the bomb and we would drop it unless they surrendered.’ Naming S-1 ‘even in that select circle … was sort of a shock,’ he would recall. ‘You didn’t mention the bomb out loud; it was like … mentioning Skull and Bones [an undergraduate secret society] in polite society at Yale; it just wasn’t done. Well, there was a sort of gasp at that.’

McCloy persevered: ‘I think our moral position would be stronger if we gave them a specific warning of the bomb.’

The President seemed interested. He urged McCloy to take up the matter with Byrnes, who would soon be sworn in as Secretary of State. McCloy did so and Byrnes swiftly killed the idea. Byrnes, as Truman knew, firmly opposed any ‘deals’ with Japan that might be considered ‘a weakness on our part’, McCloy later wrote. (For the rest of his life, McCloy would regret the ‘missed opportunity’ of 18 June, insisting that the Japanese would have surrendered had America made clear that they could retain the Emperor and warned them of the bomb. Instead, the President had ‘succumbed’ – McCloy wrote, at the age of 89, in a letter to presidential adviser Clark Clifford – ‘to the so-called hardliners’ at the State Department.)


The land invasion plans were dealt a terminal blow in early July. Further reports, based on Ultra intercepts, of mounting Japanese strength in Kyushu, turned a blowtorch on the case for Downfall. The horrific example of Okinawa focused American minds on the growing presence of Japanese troops, and armed civilians, in Kyushu. On 8 July, the Combined Intelligence Committee released an ‘Estimate of the Enemy Situation’ – sourced to Ultra, military appraisals and interrogation of prisoners. Prepared for the Joint Chiefs of Staff, it stands as one of the most authoritative assessments of Japan’s military capability in the dying days of the war. By July 1945, the report states, Japan expected to be able to field 35 active divisions and 14 depot divisions – a total of two million men (many of them worn-out or poorly trained  conscripts, or  civilians  pressed  into  uniform)  –  in defence of Kyushu and Honshu. There were, however, qualifications. Most of these men had not been deployed as of 21 July, due to service elsewhere and transport delays, leaving 196,000 Japanese troops and perhaps 300,000 male civilians fit for military service stationed in  southern Kyushu, according to US Sixth Army estimates. However, Ultra updated these estimates throughout July,  with evidence of further homeland divisions moving to Kyushu. General MacArthur, ever anxious to lead the invasion, dismissed the figures as misinformation, or simply ignored them. Meanwhile, the Olympic Medical Plan (published 31 July) estimated 30,700 American casualties within 15 days of the invasion of Kyushu (requiring 11,670 pints/5520 litres of blood); 71,000 casualties after 30 days (27,000 pints/12,770 litres); and 395,000 casualties after 160 days (150,000 pints/71,000 litres). In each case about a third of the projected casualties were listed as battlefield dead and wounded; the rest would be general illness and non-battle injuries.

Regardless of the quality of the enemy troops – and the evidence suggests they were badly equipped, relying more on spirit than any tangible factors (like adequate air cover and artillery) – their huge numbers unsettled and ultimately helped to shelve the US invasion plans. That was not because America feared it would lose the encounter; rather, hurling American lives at a defeated nation, at a people intent on their own destruction, made little sense: why  expend  American lives playing to the samurai dream of a ‘noble sacrifice’, a national gyokusai? Why assume the role of executioner to a regime determined to inflict martyrdom on its people? And at what cost? The unrelenting roll call of the American dead was politically intolerable at  a  time when the sea blockade and air war – precision and incendiary – were grinding the enemy under. And there was the wild card of the Soviet Union, whose entry into the conflict Truman continued publicly to encourage, and privately to question. Washington could not overlook the gift of Soviet arms assistance, which, the intelligence chiefs concluded, would ‘convince the Japanese of the inevitability  of complete  defeat’.

The atomic bomb, if it worked, was not seen as a direct alternative to the invasion: the invasion and the bomb were never mutually exclusive; nobody presented the case in terms of ‘if the bomb works, the invasion is off ’. These events advanced in tandem, in a complex interplay between threat and counter-threat, setback and opportunity. Indeed, some in the Pentagon believed that the bomb, if it worked, made the invasion more likely – as a supporting weapon: ‘In the original plans for the invasion,’ General Marshall later wrote, ‘we wanted nine atomic bombs for three attacks’ – on three fronts. The risk of irradiating the advancing army did not recommend the strategy.

By early July 1945, regardless of whether the bomb worked or not, Japan’s pathetic state, the likely casualties of Tokyo’s death wish, and Truman’s political sensitivity made it almost inconceivable that MacArthur’s invasion plan would proceed. Ultra  confirmed Washington’s fears – and those of the Joint Chiefs of Staff –  that Japan’s leaders had not only correctly identified where the proposed invasion would start; they had made the defence of the southern half of Kyushu their ‘highest priority’. These developments led to the decision to set aside, if not yet completely cancel, Olympic – MacArthur’s cherished invasion plan – a week before the momentous developments in the New Mexican desert.


Stimson moved further into the cold during June  and  July;  his influence waned as he made his moral reservations clearer. His  fall from grace symbolised the excision of conventional morality from the political heights of Washington. On 10 May the War Secretary had talked privately with Marshall – his closest companion in age and outlook – ‘on rather deep matters’. Stimson hoped to hold off the invasion of Japan ‘until after we had tried out  S-1  … probably  we could get the trial before the locking of arms and much bloodshed’.

Stimson privately paled at the thought of dropping the bomb on a city. And yet he had recently approved the world’s first nuclear strike, on ‘workers’ homes’. At first glance, it is difficult to see how he reconciled  these  contrary  positions. The  answer  is  that  Stimson  was above all a politician and military strategist, not an ethicist or man of God. His public image worried him more than the dictates of his conscience: he feared that his approval of the atomic attack would damage his public reputation as ‘a Christian gentleman’, as he later wrote.

The carrot of the Emperor would force Japan to surrender, he maintained. On 6 June, in a private chat with the President, he raised the possibility of achieving ‘all our strategic objectives’ without the insistence on unconditional terms. Implicit here was the gift of the Emperor. Allow this and the ‘liberal men’ in Tokyo would have a potent political weapon against their fanatical colleagues; or so Stimson hoped. Surely a class existed within Japan ‘with whom we can make proper terms’, he repeated in his diary on 18 June, the night of the meeting with the Joint Chiefs; surely the Japanese can be made to respond peacefully to a ‘last chance’ warning, he wrote, on the 19th. Hitherto, these had been his private musings; henceforth the embattled War Secretary intended to make a more public stand – in line with Grew’s moderation.

That day, in talks with Grew and Forrestal, Stimson expressed his abhorrence of the (at that time) anticipated cave-by-cave attack on the Japanese homeland. Were there not reasonable elements within the Japanese regime, he wondered, who resisted Tokyo’s death wish? Grew agreed: ‘All the blustering the Japanese were now doing about fighting to the last meant nothing; there might be important things going on in the minds of the leaders of Japan at the moment of a quite contrary character …’

America should clarify what it meant by ‘unconditional surrender’, Grew advised. For him, like Stimson, it meant letting the Japanese determine their post-war political structure – including, if they desired, the Imperial line – so long as it enshrined freedom of thought and speech, and human rights, and contained no militaristic element. It meant allowing Japan to retain the Emperor as a figurehead. Presented with those terms, he argued, Japan’s rulers would ‘desist from further hostilities’. The preservation of the throne and the ‘non-molestation’ of Hirohito, Grew later advised Truman, ‘were likely to be irreducible Japanese terms’. The intelligence community lent weight to these deliberations: in early July the Combined Intelligence Committee warned that Japan equated ‘unconditional surrender’ with the loss of the Emperor and ‘virtual extinction’. In this light, it suggested, a promise to retain the Emperor might compel the Japanese to disarm and relinquish all territory.

Stimson and Grew were not the only high officials in Truman’s administration willing  to  abandon the  unconditional  surrender formula to secure victory over Japan. Some, like McCloy, had even advised offering the Japanese a warning of the atomic  bomb. Ralph Bard, Assistant Secretary of the Navy (as well as McCloy and others at different times) urged Truman to make a show of the  weapon’s power before any military use. In a memo to Stimson on 27 June, Bard favoured an explicit warning to Japan two or three days before dropping the bomb – to demonstrate that America was ‘a great humanitarian nation’ with a strong sense of ‘fair play’. He believed that Tokyo was sincere in its efforts to find a medium of surrender; he even supported peace negotiations. This was, of course, going too  far, and few agreed with Bard.


On 2 July, the President received Stimson in the Oval Office. The War Secretary looked tired and pale. They discussed the draft of a proposed Presidential statement on the Japanese surrender. With time running out and people fretting at  the  door, Stimson  asked Truman  why  he had not been invited to join the Presidential party at the Potsdam Conference, which began that month. Had the President declined to invite him ‘on account of the fear that I could not take the trip?’ Stimson asked, casually referring to his health. ‘Yes, that was just it,’ replied Truman laughing.

But the Surgeon General has endorsed my condition, Stimson protested. And ‘practically every item on the German agenda’ – at the Berlin conference – ‘was a matter handled by the War Department’. The President said he would think it over and discuss it tomorrow. In such homely slights are powerful men brought low: the official in charge of the war would not be invited to the meeting convened to end it.

Seeing his star wane, Stimson sensed he had nothing to lose  by added candour. Later that day he wrote to the President, setting forth a nightmare vision of fanatical resistance and terrible American losses, far greater than at Okinawa, which would leave Japan ‘even more thoroughly destroyed than was the case with Germany’. Was this necessary, he wondered – not fully realising the extent to which the President agreed with him about the redundancy of the invasion plan. Surely the Japanese were on the brink of defeat? Japan had no allies, virtually no navy, and was prey to a surface and submarine blockade that deprived her people of food and supplies. Her cities were ‘terribly vulnerable’ to air attack. Against her marched not only the Anglo- American forces but also ‘the ominous threat of Russia’. America enjoyed ‘great moral superiority’ as the victim of [ Japan’s] first sneak attack. The difficulty, he conceded, was to impress upon the Japanese warlords the futility of resistance.

To this statement Stimson appended a new draft of what would become known, with important amendments and deletions, as the Potsdam Declaration (officially, the Potsdam Proclamation): a warning to the Japanese leadership to surrender or face annihilation. His words resonated with those of an earlier draft by Joseph Grew (which the President had considered ‘sound’ at the time). Both drafts allowed Japan to retain Hirohito as a powerless head of state; and promised not to enslave or ‘extirpate’ the Japanese as a race ‘or destroy them as a nation’ –  but to remove all vestiges of the military regime so that Tokyo could not mount another war. The Japanese, it concluded, should be permitted ‘a constitutional monarchy under the present dynasty’ if it be shown to the  complete  satisfaction  of  the  world  that  such  a  government ‘will never again aspire to aggression’. Crucially, the draft listed the Soviet Union as one of the four signatories, with America, Britain and China.


It was to no avail. A new, hardline force had entered the Truman administration. On his swearing in as Secretary of State, on 3 July, Byrnes swiftly assumed greater powers than his position entailed. He acted in some ways as a de facto president – and moved at once to stifle the air of compromise. In coming weeks, Truman sat back to watch Byrnes tear apart these dovish tendencies, stifle any softening of the surrender terms and thwart Stimson’s expectation of an invitation to Potsdam (the War Secretary would invite himself and attend under his own steam). Byrnes ensured that Grew, McCloy and Bard (hitherto a member of the Interim Committee) were excluded from critical meetings and their views largely ignored.

Under the new Secretary, the State Department pointedly refused to entertain ideas about retaining the Emperor. The President would be ‘crucified’ if he accepted anything less than unconditional surrender, Byrnes, with an eye on public feeling, confided to his secretary. Curiously, official US foreign policy (on unconditional surrender) made no direct reference to the Emperor – stating only that Japan must disarm and dismantle its military system – a state of ambiguity that left Hirohito’s fate the subject of raging debate and confusion in Washington and Tokyo. Nowhere was the debate more intense than in the State Department under Byrnes, which affirmed that the ‘only terms’ on which America would deal with Japan were those listed under ‘unconditional surrender’ – as announced by Roosevelt at Casablanca in 1943 – which prescribed the elimination of the military system, implicitly including Hirohito as supreme commander.

The State Department duly fell in step with Byrnes’ hardline view. The new Secretary had influential backers: Assistant State Secretary Dean Acheson, Director of the War Department’s Office of Facts and Figures Archie MacLeish and their supporters reacted violently to any suggestion of retention of the Emperor: it would be seen as exonerating a war criminal and allowing an abhorrent enemy to set the terms of surrender; the Emperor stood at the pinnacle of an odious military system, and his continuation, even as a powerless figurehead, risked the resurgence of that system. In any case, the perpetrators of Pearl Harbor, Bataan and innumerable atrocities against prisoners and civilians were in no position to impose conditions on America. The State Department hammered out these views at a staff meeting on 7 July, over which Grew awkwardly presided as Acting Secretary (Byrnes being away). Nor were there any ‘liberal-minded Japanese’, the hardliners argued: Ultra’s intercepts had revealed Tokyo’s continuing, bitter determination to fight to the last.

Byrnes’ obsession with privacy has obscured many of his words and deeds, leading some to infer what a man of his character might have done, rather than what he did, during the coming events. The Protestant convert (he grew up a Catholic) from South Carolina has been variously described as deceitful, pathologically secretive, a master of the dark arts of political arm-twisting and openly racist. Some of these criticisms are unfair. For instance, while he opposed the principle of racial integration, the central tenet behind Roosevelt’s civil liberties program, he refused to join the Ku Klux Klan at a time when it was politically expedient to do so. He shared the Klan’s basic ideas but baulked at their methods; the lynching of black men was not the politician’s way. His restraint was thought courageous at the time because, as an ex-Catholic, he had much to prove to the hooded Protestants who tended to persecute papists when blacks were scarce.

Whatever Byrnes’ flaws  or strengths, his actions  must be seen in the light of his record. He was a skilled judge and administrator, and a highly experienced politician of the kind that excelled behind the scenes on committees. His work as head of the Office of War Mobilization was exemplary at a time of national emergency. His deep knowledge of Washington and his thwarted ambition – he had hoped to succeed Roosevelt as president – quickly established him as Truman’s ‘big brother’ in political terms. As Truman’s personal ‘coach’ on sensitive areas of foreign policy, Byrnes enjoyed great influence over the President well before his elevation to Secretary of State. It was Byrnes who, handing Truman a leather-bound transcript of his Yalta notes, urged the inexperienced new leader to adopt a much tougher line on Russia. Byrnes also served as Truman’s eyes and ears on the Interim Committee, at whose 21 June meeting he overruled Stimson and drove the decision to revoke Clause Two of the Quebec Agreement with Britain and Canada, signed by Churchill and Roosevelt on 19 August 1943, which folded British atomic research into the Manhattan Project and bound the signatories not to use the atomic bomb against a third country without mutual consent. Washington had lost faith in the agreement in 1944, when it emerged that Britain had shared secret details with France in exchange for post-war patents on nuclear reactors. At Byrnes’ urging, America had thus freed herself to use the weapon unilaterally without any need to consult her allies.

This is an edited excerpt from chapter 10 of Hiroshima Nagasaki: The Real Story of the Atomic Bombings and Their Aftermath by Paul Ham, published in August 2015 by Picador USA. Copyright © 2015 by Paul Ham/Picador USA. Published by arrangement with Picador USA. All rights reserved.