Explain how the United States moved away from intervention in the Western Hemisphere and kept an isolationist approach to Europe and Asia in the 1930s

Learning goal: Explain how, during the 1930s, the U.S. government attempted to distance the country from earlier interventionist policies in the Western Hemisphere and retained an isolationist approach to events in Europe and Asia until the beginning of World War II, and explain why that approach eventually changed.

Two regions, two policies. In the 1930s American foreign policy had two strands that fit together. In the Western Hemisphere (Latin America and the Caribbean), the goal was to distance the United States from its record of intervention. Toward Europe and Asia, the goal was to retain isolationism: to avoid alliances and war. Both reflected a public mood shaped by the costs of World War I and by the Great Depression, which made domestic recovery the first priority.

Earlier interventionism. Interventionism means using military, political or economic force to shape events inside other countries. From about 1898 to the early 1930s the United States intervened repeatedly in the Caribbean and Central America. Under the Platt Amendment (1901) it claimed a right to intervene in Cuba. The Roosevelt Corollary (1904) to the Monroe Doctrine asserted a right to act as an "international police power" in the hemisphere. U.S. Marines occupied Nicaragua for most of the years from 1912 to 1933, Haiti from 1915 to 1934 and the Dominican Republic from 1916 to 1924. Latin Americans resented these occupations, and by the late 1920s U.S. leaders saw that resentment as harmful to trade and influence.

The Good Neighbor Policy. In his inaugural address in March 1933, Franklin Roosevelt pledged the nation to the policy of the "good neighbor." The pledge became concrete. At the Montevideo Conference in December 1933, the United States accepted the principle that no state has the right to intervene in the internal or external affairs of another. The last Marines had already left Nicaragua by early 1933, under Hoover, before Roosevelt took office; under Roosevelt the last left Haiti in 1934. A 1934 treaty with Cuba abrogated the Platt Amendment, though the United States kept its naval base at Guantánamo Bay. When Mexico nationalized foreign oil companies, including American ones, in 1938, the United States protested and negotiated compensation but did not send troops. Hoover's administration had begun the shift, but Roosevelt named it and carried it further. The limit: the United States still used economic pressure and continued to deal with dictators who were friendly to it, so "non-intervention" meant no troops, not no influence.

Isolationism toward Europe and Asia. Isolationism is a policy of avoiding political and military commitments to other nations, especially alliances and wars. It did not mean cutting off trade entirely. Isolationist feeling was strong in the 1930s for several reasons: disappointment that World War I had not made the world safer, the Senate's earlier rejection of the League of Nations, and the Depression. From 1934 to 1936 a Senate committee led by Gerald Nye investigated the munitions industry and suggested that bankers and arms makers had profited from drawing the country into World War I. That conclusion was contested, but it persuaded many Americans. Congress passed Neutrality Acts in 1935, 1936 and 1937. The 1935 act banned selling arms to nations at war and warned Americans that they traveled on those nations' ships at their own risk; the 1936 act banned loans to nations at war; and the 1937 act forbade Americans to travel on their ships. The 1937 law added a "cash-and-carry" rule: warring nations could buy certain non-military goods only if they paid cash and carried the goods away in their own ships.

Aggression abroad. Meanwhile, aggressive states expanded. Japan seized Manchuria in 1931 and invaded China in 1937. Italy invaded Ethiopia in 1935. Germany under Hitler rearmed, remilitarized the Rhineland in 1936, annexed Austria and took the Sudetenland in 1938, and occupied the rest of the Czech lands in March 1939. The United States protested but did not act. In October 1937 Roosevelt suggested that aggressor nations be "quarantined," but public reaction was cool and no policy followed.

Until the beginning of World War II. Germany invaded Poland on September 1, 1939, and Britain and France declared war. In November 1939 Congress allowed arms sales on a cash-and-carry basis, which favored Britain and France because they controlled the Atlantic. Policy then moved step by step: the destroyers-for-bases deal with Britain in September 1940, the first peacetime draft in 1940, and Lend-Lease in March 1941, which let the president lend or lease war materials to nations whose defense was vital to the United States. In August 1941 Roosevelt and British prime minister Winston Churchill issued the Atlantic Charter, a statement of shared aims for the postwar world, although the United States was still not at war. Isolationists organized the America First Committee in 1940 to oppose these steps. The debate ended with Japan's attack on Pearl Harbor on December 7, 1941; Congress declared war on Japan the next day, and Germany and Italy declared war on the United States on December 11.

A fully worked model. Question: were the Good Neighbor Policy and the Neutrality Acts contradictory? In their aim, no, though this is a judgment a student can argue either way. Both reduced the chance that the United States would be drawn into foreign conflicts: one by ending occupations in its own hemisphere, the other by removing the arms trade and loans that isolationists believed had pulled the nation into World War I. Both served the same priority of peace and domestic recovery. The methods differed: the Good Neighbor Policy kept up active diplomacy and trade with Latin America, while the Neutrality Acts cut off dealings with nations at war, so a student could also argue that one label hides two different strategies.

The misconception. "Isolationism meant the United States had no contact with the world." It kept trading, kept diplomatic relations and kept influence in Latin America; it avoided alliances and war.

Worked example 1 — evidence of distancing: Claim: the Good Neighbor Policy moved away from intervention. Evidence: Marines left Haiti (1934), completing a withdrawal from Nicaragua that Hoover had finished by early 1933; the Platt Amendment was abrogated (1934); the United States did not send troops when Mexico nationalized oil (1938). Limit: economic pressure and support for friendly dictators continued.

Worked example 2 — reading a law: The Neutrality Act of 1935 banned arms sales to all nations at war. Effect in the Italy-Ethiopia war: because it applied to both sides, it did not help the victim. The law's logic was to keep the United States out, not to punish aggression. This shows how isolationism could favor stronger aggressors in practice, an interpretation you can support from the case.

Worked example 3 — sequencing the shift: 1939 cash-and-carry for arms → 1940 destroyers-for-bases → 1940 peacetime draft → March 1941 Lend-Lease → December 7, 1941 Pearl Harbor. Each step moved the nation further from strict neutrality before it entered the war, which is why the standard says isolationism lasted "until the beginning of World War II" for the United States.

Two-region comparison: Draw two columns, Western Hemisphere and Europe and Asia. In each, list the earlier policy, the 1930s policy, three dated actions, and the reason given for the change. Then write two sentences explaining what the two columns have in common.

Independent performance: Take the role of a senator in 1939 and write a speech for or against repealing the arms embargo. Success criteria: accurate references to at least two events of aggression abroad with correct dates; reference to the Neutrality Acts; one argument drawn from the lessons of World War I; one acknowledgment of the opposing view; and a closing statement of your position. After writing, add a short note separating the historical facts you used from the arguments your senator makes.