Important ideological differences separated the two countries as well, especially during the postwar years, when American foreign policy officials took it upon themselves to spread democracy across the globe. This goal conflicted drastically with the Russian revolutionaries’ original desire to overthrow capitalism. Having been invaded by Germany twice in the last fifty years, Soviet leaders also wanted to restructure Europe so that a buffer existed between the Germans and the Soviet border. Both the United States and the USSR believed that their respective survival was at stake, and each was therefore prepared to take any steps to win. As a result, both countries found themselves succumbing to the classic prisoners’ dilemma: working together would produce the best result, but with everything to lose, neither side could risk trusting the other.