Answer:
The Lend-Lease Program angered isolationists because it put an end to the neutrality of the United States and was a decisive step to leave behind its traditional policy of isolationism and nonintervention, which had dominated the foreign relations of the country before World War I and again since 1935 with the passing of the Neutrality Acts; After the war, the United States would adopt a completely different role with the constant supervision and intervention in world affairs.