In what ways did Stalin make the Cold War inevitable ?

In a way, the fault for beginning the Cold War partially lies with Roosevelt as well. During the Yalta Conference, Franklin Roosevelt, Joseph Stalin, and Winston Churchill all agreed to fight Germany until it unconditionally surrendered. Stalin also agreed to free elections in Eastern Europe, and promised to enter the war against Japan after the war in Europe was finished.
Stalin already occupied Eastern Europe and his armies were starting to round up local leaders for imprisonment and replace them with Communists. Roosevelt knew this but also wanted Stalin to enter the war against Japan. Roosevelt's plan was to agree to anything Stalin wanted as long as he got a pledge of support for his war against Japan and to negotiate the fate of Eastern Europe later. Sadly, "later" never came because Franklin Roosevelt died of a brain hemorrhage weeks after the Yalta Conference.
Stalin never introduced fair elections in Europe at the war's end, his armies occupied Eastern Europe and were in the process of stripping Eastern Berlin of anything of value. When Truman called Stalin on this, Stalin insisted that his country was severely weakened by the war (which it was) and that he needed a buffer zone. Stalin kept this land under that pretense and even felt justified in doing so by the fact that the United States maintained a sphere of influence in Latin America.
Stalin also authorized the espionage needed to build the atomic bomb, thus touching off a nuclear arms race between his country and the United States. And of course, Stalin killed millions of his own people, thus leaving him open for criticism with Eastern Europeans and groups in the United States.  
https://www.history.com/topics/world-war-ii/yalta-conference