1. Condemnation and Non-Recognition: The United States condemned Japan's aggression and refused to recognize the puppet state of Manchukuo, which Japan had established in Manchuria. This stance was part of the US policy of non-recognition, which aimed to deny legitimacy to territories acquired through force.
2. Stimson Doctrine: US Secretary of State Henry L. Stimson issued a statement known as the Stimson Doctrine in January 1932. The doctrine declared that the United States would not recognize any territorial changes resulting from acts of aggression. It was a symbolic gesture of disapproval but did not involve immediate military action.
3. League of Nations Involvement: The United States supported the efforts of the League of Nations to address the Manchurian crisis. The League passed a resolution condemning Japan's actions and called for a peaceful settlement. However, Japan disregarded these efforts and continued its occupation of Manchuria.
4. Economic Measures: The United States imposed some economic measures against Japan, such as banning the export of certain goods and materials that could be used for military purposes. These measures were limited and did not significantly affect Japan's overall economy or its military capabilities.
5. Neutrality Acts: During this period, the United States had Neutrality Acts in place, which aimed to prevent the country from becoming involved in foreign conflicts. These acts restricted US citizens and companies from providing financial assistance or arms to belligerent parties. However, the Neutrality Acts did not prevent the United States from taking diplomatic actions or expressing its disapproval of Japan's actions.
6. Diplomacy and Negotiations: The United States engaged in diplomatic efforts to resolve the Manchurian crisis peacefully. It held discussions with Japan and other countries involved in the region to seek a negotiated settlement. However, these efforts were not successful, and Japan continued to consolidate its control over Manchuria.
7. Public Opinion and Isolationism: Public opinion in the United States was generally against direct military intervention in Asia. The country was focused on its own economic recovery from the Great Depression and was reluctant to become embroiled in foreign conflicts. Isolationist sentiments were strong, and there was limited support for taking military action against Japan.
Overall, the US response to the Japanese invasion of Manchuria was cautious and restrained. It used diplomatic means to express disapproval and concern but did not take significant military action or impose severe economic sanctions against Japan. The US's role was limited by its own neutrality policies, isolationist tendencies, and the broader global context of the time.