Final answer:
The main points of the Monroe Doctrine are: the United States would refrain from interfering with established European colonies in the Western Hemisphere; the United States would remain neutral and not become involved in European affairs; and any attempted interference by a European nation in the Western Hemisphere would be seen as a hostile act by the United States and dealt with accordingly.
Step-by-step explanation:
The main points of the Monroe Doctrine are:
The United States would refrain from interfering with established European colonies in the Western Hemisphere
The United States would remain neutral and not become involved in European affairs
Any attempted interference by a European nation in the Western Hemisphere would be seen as a hostile act by the United States and dealt with accordingly