November 1943: The Nazis and their Axis allies controlled nearly the entire European continent. Japan dominated the Pacific. Allied successes at Sicily and Guadalcanal had gained them modest ground but at an extraordinary cost. On the Eastern Front, the Soviet Red Army had been bled white. The path of history walked a knife<U+2019>s edge. That same month a daring gambit was hatched that would alter everything. The "Big Three"<U+2014>Franklin D. Roosevelt, Winston Churchill, and Joseph Stalin<U+2014>secretly met for the first time to chart a strategy for defeating Adolf Hitler. Over three days in Tehran, Iran, this trio<U+2014>strange bedfellows united by their mutual responsibility as heads of the Allied powers<U+2014>made essential decisions that would direct the final years of the war and its aftermath. Meanwhile, looming over the covert meeting was the possible threat of a Nazi assassination plot, code-named Operation Long Jump. Before they left Tehran, the three leaders agreed to open a second front in the West, spearheaded by Operation Overload and the D-Day invasion of France at Normandy the following June. They also discussed what might come after the war, including dividing Germany and establishing the United Nations<U+2014>plans that laid the groundwork for the postwar world order and the Cold War.