Final answer:
Roosevelt's stance on isolationism was complex; publicly, he favored neutrality, but he signaled readiness to support allies against aggression, and through the Roosevelt Corollary, he asserted a right to intervene in the Western Hemisphere. His policies reflected a balance between isolationist sentiment and the understanding of the need for international involvement.
Step-by-step explanation:
President Roosevelt acknowledged the challenge of isolating the United States from the rest of the world. He understood that although his public stance was one of strict neutrality, privately he recognized the potential necessity of aiding allies such as Britain and France. Despite the neutrality laws in place, he conveyed to European leaders that the industrial strength of the U.S. could support them in case of German aggression. Roosevelt's foreign policy also included a stern message through the Roosevelt Corollary to the Monroe Doctrine, emphasizing that the United States had the right to intervene in the Western Hemisphere to maintain stability.
This policy faced criticisms of imperialism and the U.S.'s self-interest in Latin America and the Caribbean. Moreover, during World War II, despite isolationist sentiments, Roosevelt devised the Lend-Lease program, which ultimately provided substantial support to the Allies before the U.S. formally entered the war after the Japanese attack on Pearl Harbor.