"For Stalin, even more than for his partners, the wartime alliance constituted a marriage of convenience. He never shook off his fear that the British and Americans might sign a separate peace with Hitler—he even alluded to this concern obliquely during Churchill’s visit in October 1944—and their delays in opening a second front were seen as sinister confirmation. Having turned the Nazi tide by its own efforts, the Soviet Union, he believed, must also provide for its own postwar security; for Stalin, that meant preventing Germany from becoming a threat once again, probably by dismembering the country into small states on the pre-Bismarck model. It also required a quiescent, client state in Poland—historically the gateway for German aggression. More generally, Stalin wanted to regain Russian territories lost in World War I, including eastern Poland and the Baltic states, and to expand into traditional czarist areas of influence, particularly around the Black Sea (Russia’s gateway to the Mediterranean) and on the Pacific. The concept of territorial security was therefore fundamental to his regime."