US isolationism in the 1930s

Past the US, the Great Depression was a far more international than any economic crisis prior. Global trade fell by 30 percent as nations raised tariffs to protect domestic industries, and by 1932, around 30 million people were unemployed around the world. Trends in US foreign policy had already shifted toward isolationism, with the defeat of the Treaty of Versailles a decade earlier and increasing clamor against foreign enmeshment. After the Great Depression, the US only retreated further into its shell.

Several international incidents occurred during the 1930s in Europe and China: Japan grew aggressive and seized northeast China, Italy invade Ethiopia, and Germany began to expand into Central and Eastern Europe. Furthermore, autocratic regimes also began to grow in Germany and Russia. While the US sanctioned or condoned international actions, it took no part in maintaining order or taking any action.

In 1933, Roosevelt said, during his inaugural address, "In the field of World policy, I would dedicate this nation to the policy of the good neighbor, the neighbor who resolutely... respects the rights of others, the neighbor who respects his obligations and respects the sanctity of his agreements in and with a World of neighbors."

Thus Roosevelt began the Good Neighbor policy, which strayed from any assertion of military or diplomatic force, especially in Latin America. The policy specifically tried to step away from earlier interventionalist policies imposed in the 1910s and 1920s under Teddy Roosevelt. As a result, the US pulled out of its occupation of Nicaragua, Haiti, and annulled the Platt Amendment with Cuba, which said the US had the right to intervene in Cuba to protect internal stability.

Roosevelt stated, "The definite policy of the United States from now on is one opposed to armed intervention."

Along with the Good Neighbor policy, Roosevelt enacted several policies limiting international engagement. In 1934, Roosevelt passed the Johnson Act, which prohibited loans to countries in default on their debt, and in successive years took steps to decrease loans and other exports to other countries.

Congress also took several measures to prohibit the same economic activities they believed entangled the US in World War I. In 1934, Congress created the Special Committee on Investigation of the Munitions Industry, headed by Gerald Nye, which investigated the US' World War I engagement.

However, the Special Committee came to an abrupt end in 1936. According to the US Senate website, "Nye suggested that [Woodrow] Wilson had withheld essential information from Congress.... Democratic leaders, including Appropriations Committee Chairman Carter Glass of Virginia, unleashed a furious response... Glass slammed his fist into his desk until blood dripped from his knuckles."

Still, Nye's investigations created questions about the moral grounds of the US' intervention. Many Americans felt betrayed, and public sentiment began to believe that US commercial interest had created the intervention instead.

The momentum created by Nye's investigation, along with a general increasing public favor of nonintervention after World War I and the Great Depression, turned the US inward and away from foreign entanglements. The 1930s represented a high watermark of US isolationism, which would remain until later in World War II and the second half of the 1900s.