Why did Roosevelt believe the us could not isolate itself from the rest of the world?

Roosevelt believed that the U.S. could not isolate itself from the rest of the world because global interdependence made isolationism impractical. He recognized that economic, political, and security issues were interconnected and that events abroad could directly impact American interests. Furthermore, he argued that the U.S. had a responsibility to promote democracy and stability internationally, seeing engagement as essential for maintaining peace and preventing conflicts that could ultimately draw the U.S. in regardless of its stance.