US Diplomacy During World War II: Policy and Strategy

Introduction

World War II was a watershed event in the history of international relations, particularly in the relations between the United States and the rest of the world. Before the war, US foreign policy and public opinion favored isolationism, although support for internationalism existed in some pockets as well. As a result, in the initial years of the Second World War, US diplomacy was focused on avoiding entanglement in a foreign conflict. Gradually, however, the internationalists managed to win the debate against the isolationists, and the United States not only entered the war but also played a central role in its outcome.

After the Second World War, US foreign policy became firmly internationalist — symbolized by its key role in the founding of the United Nations and its rivalry with the Soviet Union on the world stage. How this transformation in US foreign policy came about is the story of US diplomacy during the Second World War, and that is the subject of this essay.

Background: Isolationism and the Road to War

US diplomacy during the Second World War had its roots in the aftermath of the First World War. Having taken his country into that conflict to "make the world safe for democracy," President Woodrow Wilson unveiled his vision for collective world security after the war and worked fervently for his country's entry into a League of Nations. However, Wilson failed to secure the backing of Congress for his plan, and America entered an isolationist phase.

When the Second World War began in 1939, the US public — preoccupied with its domestic fight against the economic depression — was in no mood to become entangled in another foreign war. Franklin Roosevelt, who was in his second term as US President and firmly in charge of foreign policy when the war started, was by no means an isolationist himself. Nevertheless, he was acutely aware of public opposition to entering the war and, respecting the prevailing mood, initially followed a policy of neutrality despite his natural affinity with democratic Britain and his abhorrence of fascism.

Neutrality, Cash and Carry, and Lend-Lease

In response to widespread support for isolationism in the United States during the 1930s, Congress passed a series of Neutrality Acts in 1935 and 1936, aimed primarily at keeping the US out of European wars. Paradoxically, Americans felt a natural affinity toward the European democracies threatened by fascism, and President Roosevelt in particular wanted to help them while maintaining official neutrality. When full-scale war broke out in September 1939 after Hitler invaded Poland, Roosevelt persuaded Congress to revise the neutrality acts. Despite opposition from the isolationists, he managed to pass a plan known as "Cash and Carry" — a program that permitted the US to sell arms to nations able to pay for them in cash and able to transport them in their own ships. Although theoretically applicable to all nations, in practice the plan was intended to benefit Britain and France, as only those countries had the capability of sending ships to American shores for the purpose.¹

After the fall of France in June 1940 and the retreat of Allied forces from Dunkirk, Britain largely stood alone against the might of Nazi Germany. At that point, Britain lacked the financial resources to buy arms or transport them safely. Even without prior approval from Congress, President Roosevelt supplied 50 outdated US destroyers to the British Navy in September 1940 in exchange for long-term leases for US naval and air bases in eight British colonies, including British Guiana, Newfoundland, and Bermuda.² The American ships helped Britain transfer war material from the United States at a crucial moment in the conflict.

Recognizing the precarious financial state of the Allied forces and the need for a sustained aid program, Roosevelt followed up with a Lend-Lease bill that further amended the neutrality acts, allowed the use of US ships for transporting material, and did not require cash payment for purchases. Again, despite isolationist opposition, Roosevelt managed to get the Lend-Lease bill passed in both houses of Congress. By the end of the war, the United States had transferred a total of $50 billion worth of war material to the Allied countries under the program, with the bulk going to Britain and the Soviet Union. Lend-Lease was instrumental in sustaining the Allied war effort, particularly in the period before the US entered the war directly.

Conclusion

¹ The Cash and Carry program also benefited the American economy: the sale of arms helped create more industrial jobs, contributing to the US recovery from the Great Depression.

² Roosevelt later justified his arguably unconstitutional act of supplying the destroyers to Britain by pointing to the strategic gains made in acquiring the bases and by arguing that the destroyers contributed directly to American defense.