American Diplomacy in World War II

Sir Winston Churchill, 1942.
Photo caption

Sir Winston Churchill, 1942.

The most terrible war in human history, World War II was fought by the United States to achieve objectives that would not only protect the American nation from aggression but also would permanently better the lot of humankind. Sixty years after its end, the world still lives with the unfolding of its consequences—the rise and decline of the Soviet Union, the end of German aspirations to European dominance, the demise of Western colonialism, a 45-year East-West Cold War and its aftermath, the rebirth of Imperial Japan as a bastion of liberal capitalism, the rise of China as East Asia's dominant power. Whether in the continued tension between Japan and China or in the turbulence of the Middle East, the war's legacies loom large in all our lives.

This four-lesson curriculum unit will examine the nature of what Winston Churchill called the "Grand Alliance" between the United States, Great Britain, and the Soviet Union in opposition to the aggression of Nazi Germany and Imperial Japan.

The first lesson deals with the formation of the alliance, surveying the breakdown of the German-Soviet pact and the developing accord between the Soviet Union (Union of Soviet Socialist Republics) and the emerging alliance between the United States (officially neutral until December 1941) and Great Britain (at war with Germany since September, 1939). It effectively culminates with the "Declaration of the United Nations" (January 1, 1942) and subsequent aid agreements in the emergent allied front against the German-Italian-Japanese axis.

The second lesson covers the uncertain period from early 1942 through much of 1943. During much of this period the Grand Alliance was on the defensive. Even after the Soviet Union began to advance after its victory at Stalingrad, the Western powers were unable to establish a major second front in Western Europe. Whether the alliance could hold together, or whether the Soviet Union might make a separate peace, was uncertain. This lesson plan examines the tensions and the sources of ultimate cohesion within the Grand Alliance during the period that eventual victory seemed uncertain.

Lesson three covers issues concerning the future of Europe during the final phase of the wartime alliance. Among the salient questions were the fate of the Eastern European nations, the future of Germany, and the establishment of a new international organization to replace the League of Nations. Behind them all was the problem of whether the liberal, democratic West and the Marxist, totalitarian Soviet Union could continue to coexist as allies.

Lesson four focuses on two major postwar issues in Asia. The first was the American hope of establishing China as a great power despite its grave internal divisions and the insistence of the Soviet Union on dominance in Manchuria. The second was the American policy of ending Western imperialism in Southeast Asia. In both cases, American diplomacy had to grapple with the differing objectives of other important partners in the Grand Alliance. Teachers with limited time may wish to select only one of these problems for class exercises and discussions. The documents relating to each have been grouped together in order to facilitate such an option.

Throughout modern history, former Grand Alliances—including the ones that defeated Germany in World War I, Napoleon's France in the early nineteenth century, and Britain in the age of the American Revolution—had come apart once they had served their purpose. President Roosevelt and large numbers of the American people believed that the World War II Grand Alliance would have a different future. This unit invites students to think in general terms about the nature of military and diplomatic alliances. Are they generally matters of convenience and historical circumstance, or more lasting arrangements based on common basic principles?

Documents from the Yale Avalon project,, and other online resources will serve as primary sources for this lesson.

Guiding Questions

To what extent was the alliance against the Axis powers unified in values and postwar goals?

What were the major allied differences on wartime strategy and goals and how were they resolved?

Why and how did the United States attempt to preserve the Grand Alliance as American diplomats addressed European issues?

Was the American vision for postwar East and Southeast Asia flawed? If so, in what ways?

Learning Objectives

Lay out the outlooks and objectives of the United States, Great Britain and the USSR, at the beginning of World War II with some sense of areas of convergence and disagreement.

Evaluate the Atlantic Charter and the Four Freedoms as alliance goals and weigh them against the experience of the Nazi-Soviet agreements of 1939.

Explain the ways in which the USSR, the United States, and Britain differed on their approach to winning the war

Explain why the methods used to obtain the surrender of the French North African government were controversial in Britain and the United States and also disruptive of alliance unity

Explain the Anglo-American decision to require "unconditional surrender" from the Axis powers

Explain the ways in which the evolving military progress of the war affected diplomatic decision-making

Explain the ways in which the USSR, the United States, and Britain differed on the future of Germany.

Explain the differences between the three allies over the future of Eastern Europe, with particular attention to the problem of Poland.

Explain the role played by the establishment of the United Nations in inter-allied diplomacy.

Explain the ways in which the evolving military progress of the war affected diplomatic decision-making.

Draw on the online documentation to explain the American approach to the shaping of the peace.

Explain the differing viewpoints with which the USSR, the United States, and Britain approached the issue of European imperialism.

Explain the ways in which the USSR, the United States, and Britain approached the issue of the future of China and define the postwar goals of each nation.

Evaluate whether in these cases American policy was "realistic," i.e., in the best interests of the United States and/or likely to be achieved in the postwar world.