Answer:
According to the Monroe Doctrine the United States would look at any attempt by European nations attempt to colonize the Western Hemisphere as a hostile action towards America.
Explanation:
Named after James Monroe, the Monroe Doctrine was his policy of complete opposition to any colonialism by European countries in North and South America.
As a policy, it was one of the longest standing policies in the US history which was endorsed by several American Presidents.
This policy eventually gave rise to a political thought among US politicians that believed South America to be their 'backyard'. This eventually resulted in the US, meddling in the affairs of many countries over there.