The Atom Bomb, Ideologies, and the Iron Curtain
Two Visions of the Postwar World
By 1945 the wartime alliance held two fundamentally different ideas of how society should be run. The USA championed capitalism and liberal democracy: free elections, multi-party politics, freedom of the press, and an economy of competing private businesses. The USSR championed communism: a single-party state under the Communist Party, a planned economy with state-owned industry, and the ideological goal of spreading revolution to other countries. The two systems were not just different policies; each treated the other as a threat to its survival.
By 1945 the USA and USSR were the two surviving superpowers, but their ideologies were opposites. Americans feared communism would spread by force into a war-shattered Europe; Soviets feared capitalism would encircle them with hostile neighbours, just as Germany had done in 1941.
The Atom Bomb Changes the Equation
On 6 August 1945 a single American B-29 dropped an atom bomb on Hiroshima; three days later Nagasaki was destroyed in the same way. Around 200,000 people were killed, about half of them at once and the rest from burns and radiation sickness. Japan surrendered on 15 August. The military effect was decisive, but the political effect on the wartime alliance was just as great. The Soviets had only declared war on Japan on 8 August, invading Manchuria the next day. Their reward at Yalta — territorial concessions in the Far East — suddenly mattered less, because Truman had a weapon that did not need a Soviet front.
Stalin understood almost immediately that a US monopoly on atomic weapons threatened Soviet security. He had known about the Manhattan Project through Soviet espionage and now ordered Soviet scientists to match it. Through the rest of the 1940s, the bomb sat between the two former allies as both a deterrent and a provocation. Some historians describe Truman’s use of the bomb as the first move of the Cold War; others argue it was simply the last act of the Second World War. The truth is probably both: the same explosion ended one war and helped start another.
On 24 July 1945 Truman casually told Stalin that the USA had a ‘new weapon of unusual destructive force’. Truman was watching for a reaction; Stalin barely showed one. The reason became clear later: Soviet intelligence had penetrated the Manhattan Project years earlier, and Stalin already knew the bomb existed. Some scholars argue Truman timed the news of the Trinity test to harden his negotiating line at Potsdam. Others point out he had little practical choice once the test succeeded. Either way, when Hiroshima was destroyed four days after Potsdam closed, Stalin saw it not just as the end of Japan but as a message to him.
Soviet Expansion in Eastern Europe
By the end of 1945 the Red Army occupied Poland, Hungary, Romania, Bulgaria, eastern Germany and parts of Czechoslovakia and Austria. Stalin had pledged at Yalta to allow free elections in liberated countries, but the elections that took place between 1945 and 1948 were rigged or manipulated to bring local communist parties to power. Non-communist politicians were arrested, exiled or executed. By early 1948 every Soviet-occupied state was run by a single-party communist government loyal to Moscow. Stalin called this a ‘belt of friendly states’; Churchill and Truman called it conquest by stealth.
The pattern varied country by country. In Poland the rigged 1947 election confirmed the communist hold already in place. In Hungary, communists who had won only 17 per cent of the vote in 1945 used ‘salami tactics’ — slicing off rival parties one at a time — to take over by 1948. In Czechoslovakia, where communists were genuinely popular, a non-violent coup in February 1948 finished the job. The pattern was unmistakable, and the Yalta promise of free elections was, in practice, dead.
Churchill’s Iron Curtain Speech
On 5 March 1946 Winston Churchill, no longer Prime Minister, spoke at Westminster College in Fulton, Missouri, with President Truman in the audience. He warned that ‘from Stettin in the Baltic to Trieste in the Adriatic, an iron curtain has descended across the Continent’. The phrase was not new — Churchill had used ‘iron curtain’ in his May 1945 telegram to Truman — but Fulton turned it into a public diagnosis. Behind the Iron Curtain, he argued, lay capitals under Soviet influence; Soviet ambitions were not for war but for ‘the indefinite expansion of their power and doctrines’.
In the USA the speech was controversial: many Americans still hoped to keep working with the USSR, and some newspapers accused Churchill of warmongering. Truman, to keep his options open, publicly distanced himself from the speech even though he had read it in advance. In Moscow, Stalin compared Churchill’s argument to Hitler’s rhetoric on racial superiority, declaring that the Soviet sphere was a defensive necessity, not a programme for conquest. Within a year, however, US policy had shifted in Churchill’s direction: the Truman Doctrine of March 1947 echoed the Fulton diagnosis almost word for word.
A Rivalry Without a Name
By the end of 1946 the language of partnership was gone. Truman’s officials in Moscow, including the diplomat George Kennan, sent home long memos arguing that the USSR understood only firmness. Stalin’s officials briefed the Politburo that capitalist encirclement was the new strategic reality. Public opinion in both countries was beginning to catch up. The phrase ‘Cold War’ was not in common use until 1947, but the pattern was already set: an ideological rivalry, sharpened by the bomb, mapped onto a divided Europe.
Churchill’s ‘Iron Curtain’ speech at Fulton, Missouri on 5 March 1946 named the divide running from Stettin in the Baltic to Trieste in the Adriatic. It did not start the Cold War — the elections in Eastern Europe had already been rigged — but it gave the public a vocabulary for what was happening.