The diplomatic aim of the war, from the American perspective, was to obtain unconditional surrenders from Germany and Japan (Italy conceded midway) and to maintain good relations between Allied powers in order to do so. To that end, a series of high-level meetings were held between Allied leaders along with top military strategists and political aides. In the first of these, the Atlantic Conference of August 1941—before US entry into the war—President Franklin Roosevelt and British prime minister Winston Churchill met in Newfoundland to proclaim “common principles in the national policies of their respective countries.” The two leaders agreed on little else. After Pearl Harbor, another meeting was held in the White House. There, Roosevelt affirmed his nation’s commitment to the war effort and agreed with Churchill to address the problem of Germany first. The two also established a staff structure to plan and conduct the war as partners.

The diplomatic aim of the war, from the American perspective, was to obtain unconditional surrenders from Germany and Japan (Italy conceded midway) and to maintain good relations between Allied powers in order to do so. To that end, a series of high-level meetings were held between Allied leaders along with top military strategists and political aides. In the first of these, the Atlantic Conference of August 1941—before US entry into the war—President Franklin Roosevelt and British prime minister Winston Churchill met in Newfoundland to proclaim “common principles in the national policies of their respective countries.” The two leaders agreed on little else. After Pearl Harbor, another meeting was held in the White House. There, Roosevelt affirmed his nation’s commitment to the war effort and agreed with Churchill to address the problem of Germany first. The two also established a staff structure to plan and conduct the war as partners.

In the Casablanca Conference of January 1943, Roosevelt and Churchill settled on a number of strategic goals. The control of German U-boats in the Atlantic was identified as a priority, as was completion of the campaign against German and Italian forces in North Africa. This would be followed by the invasion of Italy (beginning with Sicily) and the launching of a major bombing offensive against Germany. The cross-Channel invasion of France was postponed until 1944. A second Washington conference (May 1943) largely affirmed these objectives and, in addition, provided assistance to the Chinese air force in its fight against Japan. Similarly, a conference in Quebec (August 1943) helped to focus military operations.

November 1943 saw the meeting of Churchill and Roosevelt, along with Chinese Nationalist leader General Chiang Kai-shek, in Cairo. The start of a campaign in Burma was endorsed, and it was agreed that China would have any territory returned to it that had been lost to Japan during the war. Later that month Roosevelt and Churchill were joined by the Soviet premier Josef Stalin in Tehran, where the invasion of France in May 1944 was confirmed, to be bolstered by a Russian offensive in the east. This was followed by a second Cairo conference (December 1943), where the Burma campaign was postponed, and a second Quebec conference (September 1944), where preliminary postwar plans for Germany were devised.

At the Yalta (Crimea) Conference of February 1945, the big three—Churchill, Roosevelt, and Stalin—again discussed plans to divide Germany into occupation zones and agreed to the Soviet possession of Poland. Also at Yalta the basis of the new United Nations was laid. Finally, at the Potsdam Conference of July-August 1945, Roosevelt, now deceased, was replaced by President Harry Truman and Churchill, having lost an election at home, was replaced toward the end of the meeting by Clement Attlee. Most of the conference’s business concerned postwar Europe, including the conducting of war crimes trials before an international tribunal.