The United States pursued "isolationism" in its diplomacy in the 1920s. What is isolationism?

First of all, the United States is a country with European cultural traditions, but the distrust of Europe in American history is one of the factors leading to the formation of isolationism. The United States itself was founded by people who opposed Europe. They came to the North American continent and established a way of life different from that of Europe. In the eyes of Americans at that time, the European continent was full of darkness and corruption, which was unhealthy morally and politically. Therefore, political involvement in European affairs will violate the "ideal" of the United States and may even endanger the "democratic" system of the United States. On the contrary, Americans have a strong sense of mission to bring their "civilization" to Asia. This is a supplement to its distrust of Europe. It is this religious sentiment that has become an important reason why isolationists favor interference in Asian affairs.

Secondly, in Asia, isolationism tends to be interventionist for racial reasons.

The United States is an immigrant country, and the multi-ethnic background of American society, which is dominated by European immigrants, urges politicians to implement the policy of isolation from the European continent. Because immigrants from different countries have different historical backgrounds and national interests. Being involved in European wars or political crises will lead to open struggles among Germans, Irish, French, Italians, Poles and British and Americans. For example, on the eve of World War II, British-born and French-born Americans demanded that the US government take the side of Britain and France and enter the anti-fascist war, while German-born and Italian-born Americans supported the isolationist policy and opposed the US participation in the war. For the U.S. government, the implementation of a nationalist policy that emphasizes that the United States does not intervene in European affairs and adopts a neutral attitude towards the balance of power in Europe will help alleviate the ethnic contradictions in this multi-ethnic country. However, the attitude towards involvement in Asian affairs is different. Historically, the number of Asian ethnic minorities was small and did not occupy an important position in domestic politics. Therefore, the involvement of the United States in Asian politics will generally not cause heated debates among Asian Americans, nor will the US government face strong political pressure from Asian immigrants. This gives the United States greater freedom in deciding its Asian policy. This is also the reason why the United States was able to adopt a positive interventionist policy in Asia in the 20th century.

Third, it is required to maintain freedom of action in foreign relations and avoid being restricted by other countries, which is also the reason why the United States adopts different attitudes towards its involvement in European affairs and Asian affairs.

One of the basic propositions of isolationism is unilateralism. Historically, this proposition requires avoiding long-term political obligations to other countries in order to maintain the absolute "freedom of choice" in American foreign policy. Isolationists believe that unilateralism is an independent policy in foreign relations, which enables the United States to avoid being subject to other big powers and thus act in accordance with its own interests at any time. Starting from this proposition, isolationists worry that getting involved in European disputes will lead to the formation of a de facto alliance between the United States and European powers such as Britain and France, and it will be difficult to maintain the complete freedom of the United States in its actions. In Asia, things are different. There, no country is strong enough to restrain the United States from deviating from the principle of unilateralism. In the 1930s, unilateralism was manifested in opposing the Roosevelt administration's policy of forming an alliance with Britain and France. Isolationists oppose involvement in European wars, believing that war means a de facto alliance with Britain and France, which leads to substantial long-term involvement in European affairs. On the contrary, isolationists in the 1930s believed that the Asian war was aimed at Japan. Since Japan is the only powerful country in Asia, even if it is involved in the war, the United States can act independently without making its wartime or post-war policies subject to powerful allies. In the words of Party Senator Taft, a representative figure of isolationism in 1930s, "getting involved in the Pacific War is not as dangerous as getting involved in the European War".