Despite his euphoria over the bomb, Churchill was by now physically, if not mentally, exhausted. And as the PM’s health deteriorated, Eden increasingly took on the responsibility for the British delegation at Potsdam. ‘The PM is not mastering his brief,’ Lord Moran noted, ‘he is too tired to prepare anything.’ Yet Churchill was invigorated by the new military and political advantage that the bomb had given the West. ‘He was completely carried away,’ noted Field Marshal Brooke, ‘and was delighted to think that the bomb could redress the power balance with Stalin. “Now we could say,” Churchill enthused, “if you insist on doing this or that, well we can just blot out Moscow, then Stalingrad, then Kiev, then Kuibyshev, Karkhov, Sebastapol [sic]. And now where are the Russians!!!!”’ Brooke later conceded that Churchill was right to appreciate that the atomic bomb had shifted the balance of military power:
Winston’s appreciation of its value in the future international balance of power was certainly far more accurate than mine. But what was worrying me was that with his usual enthusiasm for anything new, he was letting himself be carried away by the very first and rather scanty reports of the first atomic explosion. He was already seeing himself capable of eliminating all the Russian centres of industry and population, without taking into account any of the connected problems, such as delivery of the bomb, production of bombs, possibility of Russia also possessing such bombs etc. He had at once painted a wonderful picture of himself as the sole possessor of these bombs and capable of dumping them where he wished, thus all powerful and capable of dictating to Stalin!
The atomic bomb had clearly reignited Churchill’s hopes of Unthinkable, though as Brooke reflected, it was the US who had the bomb and controlled its use, and not Britain. Even then, in 1945 there were great logistical problems in dropping an atom bomb. It was one thing for a B–29 bomber to pass through heavily depleted Japanese air defences, but quite another to attempt to penetrate a web of densely packed anti-aircraft defences across the Soviet Union. The aircraft bearing the bomb would have to fly at night, negotiate heavy ground fire and fighter inceptors, and then drop its bomb from a high altitude using radar, for which scope returns had to be prepared. Because at this stage US policy was still defiantly set on a course of accommodation with Stalin, there was little chance of a ‘first-strike’ against the Soviet Union. Anyway, the stock of atomic bombs was still extremely limited and until the development of rocket delivery, there remained the hindrance of enemy defences shooting down any bomb-laden aircraft.
Although Churchill had thrown in a number of Soviet city targets, such target data, especially east of Moscow, was very basic and few accurate maps existed. Even if these sites could be identified, factories manufacturing aircraft, ordnance and ball-bearings were heavily defended. The atomic bomb delivery aircraft, the B–29, had a radius of some 2,000 miles, so when it was operating out of US airbases only a limited number of Soviet targets could be attacked. The alternative was to operate from forward air bases in Europe, such as East Anglia, or Foggia, in Italy, but none of these had the necessary weapons pits for loading or facilities to store the atomic bombs. At this stage no one knew the effect of an atomic blast on a city, but since most Japanese population centres comprised wooden buildings, it was assumed that the devastation would be complete. Conversely, a Soviet concrete-built city could expect to survive total demolition.
While Japan remained oblivious to its fate, Churchill would shortly know his political future. He had already discussed the outcome of the British general election with Stalin, and, as far as the Soviet dictator was concerned, Churchill would be returned with a majority of eighty seats. Stalin was adamant that an army always voted for a strong premier. On 25 July the conference was suspended while Churchill, Eden and Attlee flew to London to discover the election results. They were due to return to Potsdam two days later, but there was a dramatic outcome. Remembering the pre-war shortcomings of the Conservative Party, rather than its leader’s wartime record, the country gave the Labour Party a landslide victory. Churchill, exercising that extraordinary will and strength, refused to flinch at the electoral upset. Those around him were stunned, though his family, and particularly his daughter Mary, offered huge support. She recalled a weekend at the prime minister’s retreat, Chequers, when, for the last time, the family entered their names in the visitors’ book. It was a volume full of the names who had dictated the fortunes of war, but now the PM signed off with one word – ‘Finis’.
In Potsdam Stalin was staggered at the result and couldn’t comprehend that Churchill couldn’t ‘fix’ it. The result caused Stalin some concern, because now he had lost both his equals. First, in April, Roosevelt had died and now, in July, Churchill had disappeared. The loss meant that the old triumvirate had melted away and Stalin became even more paranoid now that he had to deal with untested replacements. On the same day that the British contingent were away, Poland came up on the agenda. To Truman it seemed settled business. ‘Russia helped herself to a slice of Poland,’ he complained, ‘and gave Poland a nice slice of Germany, taking also a good slice of East Prussia for herself. Poland has moved in up to the Oder and the west Neisse, taking Stettin and Silesia as a fact accomplished.’ The Soviet-sponsored Polish provisional government had moved quickly to acquire this territory, and started to expel the millions of ethnic Germans, but it was a new boundary that neither Roosevelt nor Churchill had officially approved.
Two new faces appeared at Potsdam – Clement Attlee, the Labour Prime Minister of Britain, together with his foreign secretary, Ernest Bevin. This caused the Soviets some consternation; Molotov was suspicious of the new British leaders, and repeatedly asked Attlee why he didn’t know the result of the general election beforehand. The new leaders’ styles were totally different to Churchill and Eden. Attlee had little charisma but was technically master of his brief, whereas Bevin was the complete opposite of his suave, patrician predecessor and was only too happy to point it out. When returning from his first trip to America, waiting reporters were eager to record his experience. ‘What are your first impressions of America?’ they shouted. Bevin did not pause for a second. ‘The newspapers are too big,’ he replied, ‘and the lavatory paper is too small.’
Even though Bevin lacked the finesse of Eden, he continued much the same foreign policies, particularly the continued alliance with the US. He was anti-communist and had spent much of his political life fighting communist influence within the trade union movement. Indeed, Bevin arrived in Potsdam ‘fully aware of the tensions that existed and with a shrewd assessment of the scope of Soviet ambitions, a much shrewder one at this stage, than most of the Americans’. However, despite Bevin’s undoubted talents, he was at odds with many in his own party who wished to see a ‘Third Force’ of socialists within Europe, unaligned with either the US or the Soviet Union. Bevin was essentially an imperialist and believed that the best way to defend the British Empire was by a military and atomic deterrent, whereas Attlee’s hopes for security were largely vested in the emerging United Nations. Consequently, while Bevin and his immediate advisors might have agreed with the provisions of Operation Unthinkable, he would have faced an uphill struggle against Attlee and a large part of the Labour party.
On 6 August 1945 a specially adapted Boeing B–29 Superfortress, Enola Gay, set off for Hiroshima to deliver the innocently named ‘Little Boy’ uranium bomb. The target city was an important embarkation port, industrial centre and was also the site of a large military depot. The bomb took 43 seconds to fall, burst at 2000ft above the city and destroyed 70 per cent of the buildings. Estimates of those immediately killed range from 70,000 to 90,000. It was devastating but Truman had no remorse over the use of the atomic bomb, and had little patience with those who did. J. Robert Oppenheimer, who had been a key figure in the Manhattan Project, afterwards expressed doubt about the morality of using the bomb, but was dismissed by Truman as a ‘cry-baby’. After the Hiroshima bomb the Japanese attempted to petition the Soviet Union for a treaty, but in response Stalin declared war on Japan and the Red Army invaded Manchuria. It was true that this Soviet action had been agreed at Yalta, but its timing was an example of Stalin’s talent for opportunism.
On 9 August the US dropped a second, more powerful plutonium bomb on the industrial port of Nagasaki, killing in excess of 50,000 inhabitants. Still, the Japanese military refused to surrender, but it was the intervention, his only intervention during the war, of Emperor Hirohito that pressed them to surrender. Under his direction there was no loss of face. He declared the war over but never mentioned the word defeat, and Japan formally surrendered on 2 September. Unsurprisingly, this was a huge relief to the US military, for there would be only one more atomic bomb in stock until several more were produced the following month. Consequently, Churchill’s idea that the West could threaten to obliterate the Soviet Union in 1945 was very wide of the mark.
Stalin had made some important strategic gains from his war with Japan, and he was not about to concede his territorial designs in the West. Barely a week after the Japanese surrender, his foreign minister, Molotov, was involved in bitter wrangling with his counterparts in the West over recognition of the Soviet puppet governments in Europe. It seems that at the same time as this deterioration in relations, Stalin had discovered some startling information about British intentions. Oleg Tsarev, an ex-KGB journalist, has alleged that in September 1945 Stalin received his first high-level intelligence on a British strategic post-war plan. ‘The Security of the British Empire’, dated 29 June 1945, was a memorandum prepared by the British Post-Hostilities Planning Staff and had found its way onto Stalin’s desk. It was not as detailed as the Unthinkable plan, nor did it involve the US, but it was still a highly restricted document exposing British strategic thinking. There was a deluge of such documents coming into Stalin’s possession, for by the end of the war Soviet agents, including such high-fliers as Kim Philby, were operating in the very heart of Whitehall. He was head of anti-Soviet operations (Section IX) within the Secret Intelligence Service (SIS) and probably procured the ‘British Empire’ document for the NKVD. One of his SIS colleagues later confided that Philby had ‘ensured that the whole post-war effort to counter Communist espionage became known in the Kremlin. The history of espionage records few, if any, comparable masterstrokes.’
As well as Philby, there were other well connected Soviet spies supplying intelligence papers to Stalin. John Cairncross, who had previously worked for the ULTRA operation at Bletchley Park, was another SIS officer who turned traitor – at the time of VE Day, Cairncross worked for Section I, devoted to Political Intelligence. Anthony Blunt, who had worked for MI5 during the war, also proved to be of great help to Soviet intelligence and, in the words of a senior figure in their Foreign Intelligence Directorate, ‘had carried out such huge, titanic work for us’. He had also successfully run a sub-agent, Leo Long, who served in military intelligence during the war and then continued to work as a mole within the British Control Commission in Germany, rising to the post of Deputy Director of Intelligence.
The NKVD had two further moles within the British Foreign Office: Donald Maclean was First Secretary of the British Embassy in Washington, a sensitive post which was often diplomatic cover for senior intelligence officers. Another was Guy Burgess, who had left the BBC in June 1944 to take up a post in the press department of the Foreign Office. According to the former KGB agent Vasili Mitrokhin, during the period January to June 1945, Burgess supplied copies of 389 FO documents classified as ‘top secret’ to his Soviet handlers. He would regularly take a holdall full of these sensitive papers out of his office and meet his Soviet contact in a park. On one occasion he and his handler were even stopped by the police, who thought his bulging case looked like the proceeds of a robbery, but Burgess promptly convinced the officers that he had no housebreaking equipment on him. They then apologised for troubling him and his silent friend.
With the subsequent election of the Attlee government in July 1945, Burgess obtained even greater access to secret government papers, via his appointment as an aide to Hector McNeil, Parliamentary Under-Secretary of State at the Foreign Office. It is not known whether the details of the tightly restricted Operation Unthinkable ever reached Stalin, though he had certainly received details of earlier reports prepared by the British Post-Hostilities planners. Such information was passed on by Donald Maclean, known in secret Soviet transcripts as ‘Homer’. He also regularly supplied his Soviet handlers with complete copies of telegrams between Churchill and Truman that often contained details of British tactics used in the argument over the composition of a Polish government. Consequently, Stalin knew all about the differences between Britain and the US over Poland, as well as their anxious exchanges about the fate of the sixteen Polish underground leaders.