How did isolationism become quite impossible for the United States after the Spanish-American War?

1. The Spanish-American War: The Spanish-American War in 1898 marked a turning point in United States foreign policy. The U.S. emerged as a world power following its victory over Spain, gaining control over territories such as Puerto Rico, Guam, and the Philippines.

2. Expansion of Interests: With these new territories, the U.S. had expanded interests that required protection. This made it increasingly difficult for the U.S. to maintain a policy of isolationism, as it now had overseas territories to defend and manage.

3. Economic Factors: The late 19th and early 20th centuries were a time of rapid industrialization and economic growth in the U.S. This growth led to an increased need for foreign markets and resources, making isolationism impractical.

4. Global Influence: The victory in the Spanish-American War also increased the U.S.'s standing on the global stage. The U.S. began to take a more active role in international affairs, participating in events such as the negotiation of the Treaty of Paris, which ended the war.

5. Shift in Policy: All these factors led to a shift in U.S. foreign policy away from isolationism. The U.S. began to pursue a policy of interventionism, getting involved in foreign conflicts and affairs when it was in the country's interest.

In conclusion, the Spanish-American War marked the end of isolationism for the U.S. due to the expansion of American territories and interests, economic growth, and increased global influence.