Which policy declared that intervention by other nations in the Americas would be viewed as a hostile act by the United States?

Which policy declared that intervention by other nations in the Americas would be viewed as a hostile act by the United States?

• A. Open Door Policy
• B. Monroe Doctrine
• C. Truman Doctrine
• D. Roosevelt Corollary

Answer: (B)

The Monroe Doctrine. It proclaimed that European powers should keep out of the Western Hemisphere and that any attempt by other nations to intervene or colonize in the Americas would be viewed as a hostile act against the United States. This established a U.S. stance to oppose external meddling in the region and to protect newly independent countries in the Americas. The other policies mentioned address different regions or aims (Open Door Policy in China, Truman Doctrine to contain communism, Roosevelt Corollary extending intervention under U.S. authority in Latin America), so they don’t match this specific statement about how the United States would interpret outsiders’ actions in the Americas.

The Monroe Doctrine. It proclaimed that European powers should keep out of the Western Hemisphere and that any attempt by other nations to intervene or colonize in the Americas would be viewed as a hostile act against the United States. This established a U.S. stance to oppose external meddling in the region and to protect newly independent countries in the Americas. The other policies mentioned address different regions or aims (Open Door Policy in China, Truman Doctrine to contain communism, Roosevelt Corollary extending intervention under U.S. authority in Latin America), so they don’t match this specific statement about how the United States would interpret outsiders’ actions in the Americas.