Tehran, Yalta, Potsdam: Why were the wartime/post-war conferences so important?
If you have ever studied the Second World War or the Cold War, you will have heard of the Yalta and Potsdam Conferences, possibly even the Atlantic, Tehran, and Casablanca Conferences. What were these events, and how does learning about them contribute to our understanding of the events that followed?
Before we can understand why these conferences were so significant, we need to think about the wider geopolitical context of the time.
On 1 September 1939, Nazi Germany invaded Poland. Bound by a mutual defence pact, Britain and France issued an ultimatum which demanded that Germany withdraw. When Hitler refused, the Allies declared war on Germany on 3 September 1939. The Soviet Union (USSR) had initially invaded Poland alongside Germany and acted as a neutral co-aggressor, in accordance with the terms of the Molotov-Ribbentrop Pact. After Germany launched Operation Barbarossa and invaded the USSR in June 1941, which rendered the Pact void, the USSR formally entered the war on the side of the Allies. The USA then joined the war alongside the Allies in December 1941, following Japan’s attack on Pearl Harbor. France had fallen eighteen months earlier and was divided between the Occupied Zone (in the north, under Nazi control) and Vichy France (in the south, under a nominal French government sympathetic to the Nazi regime).
Therefore, by the end of 1941, the two sides were as follows:
The Allies: Britain (alongside its colonies and dominions), USSR, USA, China (who had been fighting the Japanese since 1937, before officially uniting with the Allies in December 1941)
The Axis powers: Germany, Japan, Italy (alongside Hungary, Romania, Slovakia, Bulgaria, and Croatia, who joined in 1940-41)
The war in Europe ended on 8 May 1945, after Germany signed an unconditional surrender following Hitler’s death. Subsequently, the USA dropped two atomic bombs on Japan—first on Hiroshima on 6 August, then on Nagasaki on 9 August—which led to Japan’s surrender on 14 August. The war officially ended on 2 September 1945, when Japan signed the Allies’ formal surrender terms. Tensions, however, were far from over. As one war ended, another began. This time, though, it was a ‘Cold’ War, with no actual fighting but plentiful hostility, spying, and surveillance. The relationship between the USA and USSR—or the ‘East’ and the ‘West’—became so tense that at the height of the Cold War in October 1962, the world reached the brink of nuclear war.
To understand how the USA and USSR went from fighting together in the Second World War to pointing ships full of nuclear missiles at each other and shooting down spy planes in just a couple of decades, we need to go back in time and visit the dynamics and events of the wartime conferences.
Colourised historic photo of Allied leaders Clement Attlee, Harry S. Truman, and Joseph Stalin seated together during the Potsdam Conference in July 1945.
Atlantic Conference
Who? Winston Churchill (Prime Minister of Britain) and Franklin D. Roosevelt (President of the USA)
When? 8-11 August 1941
Where? Newfoundland, Canada
What was discussed? The Atlantic Charter, which was a declaration of “certain common principles” shared by Britain and the USA. In practical terms, the Charter was an agreement confirming that neither Britain nor the US sought territorial gains from the war and which stated that both countries supported self-determination (a country's right to rule itself) and self-government. Importantly, Churchill did not accept that the latter policy applied to Britain’s colonial territories, but rather claimed that it only referred to the European countries occupied by Germany and, later, by the USSR.
Why was it important? It was the first time that Churchill and Roosevelt met as wartime leaders, and it culminated in the signing of the Atlantic Charter, which cemented the Allies’ vision for the post-war world.
Casablanca Conference
Who? Winston Churchill, Franklin D. Roosevelt, Charles de Gaulle (leader of Free French forces), Henri Giraud (French leader with US support)
When? 14-24 January 1943
Where? Casablanca, Morocco
What was discussed? The Allies’ strategy and tactics for their campaign in Italy and the bombing raids in Germany.
Why was it important? It was the first time that Roosevelt and de Gaulle met. The Allies declared their commitment to demanding the ‘unconditional surrender’ of the Axis powers.
Tehran Conference
Who? Winston Churchill, Franklin D. Roosevelt, Joseph Stalin (leader of the USSR)
When? 28 November-1 December 1943
Where? Tehran, Iran
What was discussed? The opening of a second front for the Allies to invade northern France, the Soviet commitment to declaring war on Japan, the unconditional surrender and subsequent demilitarisation and occupation of Germany, and the creation of the United Nations.
Why was it important? It was the first time that the ‘Big Three’ (Churchill, Roosevelt, Stalin) all met. The Allies formally committed to Operation Overlord (the invasion of northern France) and began negotiations over the political future of Europe, particularly regarding the post-war borders of the occupied countries.
Yalta Conference
Who? Winston Churchill, Franklin D. Roosevelt, Joseph Stalin
When? 4-11 February 1945
Where? Yalta, USSR
What was discussed? The Yalta Conference took place towards the end of the war, by which point it was clear that the Allies would win and Germany would lose. The meeting was held to discuss and finalise the Allies’ plans for the defeat of Germany and the post-war reorganisation of Europe.
Why was it important? Several key decisions regarding the post-war world were made. The Allies agreed that Germany would be divided into four occupation zones, controlled by Britain, France, the USA, and the USSR. As Berlin, the capital city, fell in the Soviet sphere, it would be divided similarly. The leaders also agreed to establish the UN after the war ended, with the USA successfully securing veto power for permanent members of the Security Council. Thirdly, the Allies agreed that free and democratic elections would be held in Eastern Europe. This was important in the context of Soviet expansionism. Ultimately, this was not upheld, as the USSR installed Communist governments and oversaw single-party elections that did not allow genuine democratic choice. Finally, Stalin agreed to declare war on Japan within three months of Germany's surrender.
Potsdam Conference
Who? Joseph Stalin, Harry S. Truman (President of the USA following Roosevelt’s death in April 1945), Winston Churchill (until 26 July when he lost the UK general election), who was replaced halfway through by Clement Attlee, the new British Prime Minister
When? 17 July-2 August 1945
Where? Potsdam, Germany
What was discussed? The unconditional surrender of Japan and the Allies’ policy for the defeated Germany.
Why was it important? The Potsdam Conference was the first meeting between the Allies after the war in Europe had ended. There were two leadership changes before and during the conference. The US president, Harry Truman, neither liked nor trusted Stalin and made his feelings clear. Tensions began to rise as the Allies finalised the post-war order and demanded Japan’s unconditional surrender.
So, why were the wartime and post-war conferences so significant?
They reveal key information about the dynamics and relationships between the leaders of the Allies, providing crucial context for major developments of the Second World War and Cold War. For example, the Atlantic Conference led to a public declaration about the common values and principles shared by the USA and Britain, at a time when Churchill desperately wanted the USA to formally join the war. The final conference, which took place between Germany’s and Japan’s surrender, saw the deteriorating relationship between the USA and USSR, further worsened when the USA dropped two atomic bombs on Japan shortly after the conference ended. It was at this point in 1945 that the Cold War began.
In sum, we cannot fully comprehend the trajectories of the twentieth century without understanding the wartime conferences: who met who and when, what was discussed, and the broader significance of the agreements (or disagreements) reached. These were the meetings that would change the course of history forever, setting the stage for a modern geopolitical landscape.
