structural:summarization
Foreign policy (1933–1941)

The main foreign policy initiative of Roosevelt's first term was the Good Neighbor Policy, which was a re-evaluation of U.S. policy toward Latin America. The United States frequently intervened in Latin America following the promulgation of the Monroe Doctrine in 1823, and occupied several Latin American nations during the Banana Wars that occurred following the Spanish–American War of 1898. After Roosevelt took office, he withdrew U.S. forces from Haiti and reached new treaties with Cuba and Panama, ending their status as U.S. protectorates. In December 1933, Roosevelt signed the Montevideo Convention, renouncing the right to intervene unilaterally in the affairs of Latin American countries. Roosevelt also normalized relations with the Soviet Union, which the United States had refused to recognize since the 1920s. He hoped to renegotiate the Russian debt from World War I and open trade relations, but no progress was made on either issue and "both nations were soon disillusioned by the accord."

The rejection of the Treaty of Versailles in 1919–1920 marked the dominance of non-interventionism in American foreign policy. Despite Roosevelt's Wilsonian background, he and Secretary of State Cordell Hull acted with great care not to provoke isolationist sentiment. The isolationist movement was bolstered in the early to mid-1930s by Senator Gerald Nye and others who succeeded in their effort to stop the "merchants of death" in the U.S. from selling arms abroad. This effort took the form of the Neutrality Acts; the president was refused a provision he requested giving him the discretion to allow the sale of arms to victims of aggression. He largely acquiesced to Congress's non-interventionist policies in the early-to-mid 1930s. In the interim, Fascist Italy under Benito Mussolini proceeded to overcome Ethiopia, and the Italians joined Nazi Germany under Adolf Hitler in supporting General Francisco Franco and the Nationalists in the Spanish Civil War. As that conflict drew to a close in early 1939, Roosevelt expressed regret in not aiding the Spanish Republicans. When Japan invaded China in 1937, isolationism limited Roosevelt's ability to aid China, despite atrocities like the Nanking Massacre and the USS Panay incident.

Germany annexed Austria in 1938, and soon turned its attention to its eastern neighbors. Roosevelt made it clear that, in the event of German aggression against Czechoslovakia, the U.S. would remain neutral. After completion of the Munich Agreement and the execution of Kristallnacht, American public opinion turned against Germany, and Roosevelt began preparing for a possible war with Germany. Relying on an interventionist political coalition of Southern Democrats and business-oriented Republicans, Roosevelt oversaw the expansion of U.S. airpower and war production capacity.

When World War II began in September 1939 with Germany's invasion of Poland and Britain and France's declaration of war on Germany, Roosevelt sought ways to assist Britain and France militarily. Isolationist leaders like Charles Lindbergh and Senator William Borah successfully mobilized opposition to Roosevelt's proposed repeal of the Neutrality Act, but Roosevelt won Congressional approval of the sale of arms on a cash-and-carry basis. He also began a regular secret correspondence with Britain's First Lord of the Admiralty, Winston Churchill, in September 1939—the first of 1,700 letters and telegrams between them. Roosevelt forged a close personal relationship with Churchill, who became Prime Minister of the United Kingdom in May 1940.

The Fall of France in June 1940 shocked the American public, and isolationist sentiment declined. In July 1940, Roosevelt appointed two interventionist Republican leaders, Henry L. Stimson and Frank Knox, as Secretaries of War and the Navy, respectively. Both parties gave support to his plans for a rapid build-up of the American military, but the isolationists warned that Roosevelt would get the nation into an unnecessary war with Germany. In July 1940, a group of Congressmen introduced a bill that would authorize the nation's first peacetime draft, and with the support of the Roosevelt administration, the Selective Training and Service Act of 1940 passed in September. The size of the army increased from 189,000 men at the end of 1939 to 1.4 million in mid-1941. In September 1940, Roosevelt openly defied the Neutrality Acts by reaching the Destroyers for Bases Agreement, which, in exchange for military base rights in the British Caribbean Islands, gave 50 American destroyers to Britain.