Immediately after the Yalta Conference (held February 4–11, 1945), Churchill said to a member of his staff: “Poor Neville Chamberlain believed he could trust Hitler. He was wrong. But I don’t think I am wrong about Stalin.” By the end of the year, he realized that he was wrong about Stalin, possibly as wrong as Chamberlain was on Hitler. He was convinced that the Soviets were acting like a Great Empire and were after world domination. He wanted to develop a strong policy to counter the Soviet threat, but he no longer had the power. He had lost the election. Clement Attlee of the Labor Party had become the Prime Minister in July 1945.
As head of the Conservative Party and Leader of the Opposition, Churchill tried to build public opinion against the Soviets. On 5 March 1946, he gave his “Iron Curtain” speech. He said, “From Stettin in the Baltic to Trieste in the Adriatic, an Iron Curtain has descended across the continent. Behind that line lie all the capitals of the ancient states of Central and Eastern Europe. Warsaw, Berlin, Prague, Vienna, Budapest, Belgrade, Bucharest and Sofia, all these famous cities and the populations around them lie in what I must call the Soviet sphere.” He noted that the expansive and evangelical philosophy of the Soviets was a threat to the West.