The Yalta Conference certainly was not the cause of the Cold War, but it did indirectly contribute to it. First, a little background: The conference was held as Nazi Germany was on the verge of defeat. However, it was the Soviets who were doing a better job of pushing back...
The Yalta Conference certainly was not the cause of the Cold War, but it did indirectly contribute to it. First, a little background: The conference was held as Nazi Germany was on the verge of defeat. However, it was the Soviets who were doing a better job of pushing back the German forces. They were nearly at Berlin while the British and American armies had barely pushed into Germany. This gave Stalin a much stronger position at the conference.
Stalin and FDR had different objectives. FDR wanted to secure Russia's help in defeating Japan. Stalin wanted to extend his influence into Eastern Europe in order to create a buffer zone against the West. To this end, Stalin agreed that Russia would join the war against Japan three months after the defeat of Germany but would also be tasked with restoring the nations of Eastern Europe. Stalin promised that the Soviet Union would allow free democratic elections to take place in these countries, something that Churchill insisted on.
However, just a month after the Yalta Conference, Stalin backed out of this promise. When 16 members of the exiled Polish government were invited to Moscow to discuss establishing free Polish elections, they were arrested and sent to the gulag. Similar anti-democratic actions were taken in the rest of Eastern Europe and puppet-states of the USSR were established. This all resulted in the division of Europe between the democratic West and the communist East, a hallmark of the Cold War.
You can look at the Yalta Conference this way: Churchill and FDR had little choice but to make this devil's bargain with Stalin. By agreeing to give up influence over Eastern Europe they were avoiding a likely fight with the Soviets. There were some, such as General Patton, who felt that the war should be continued against the Soviets in order to truly restore democracy in Eastern Europe. However, most people wanted to avoid another world war and realized that this uneasy agreement, aka The Cold War, was a better alternative.