After World War 1, the United States pursued a policy of isolationism. President Wilson had proposed the 14 Points and helped establish the League of Nations, but Americans lost trust in him for entering WWI. The US rejected the Treaty of Versailles and did not join the League of Nations. Through the 1920s, the US enacted tariffs and quotas to reduce foreign trade and immigration. This isolationism aimed to cut ties with Europe and protect American jobs and values from foreign influence, but ultimately undermined international cooperation and the League's effectiveness.