What was a primary assertion of the Monroe Doctrine?

The primary assertion of the Monroe Doctrine was that the United States would not tolerate European colonization in the Americas. Declared in 1823 by President James Monroe, this doctrine established a significant foreign policy principle intended to oppose any further European intervention in the Western Hemisphere. The reasoning behind this was rooted in a desire to protect the newly independent countries in Latin America from European re-colonization efforts and to assert the United States’ influence in the region. The Monroe Doctrine effectively warned European powers that any attempt to expand their influence into the Americas would be viewed as a threat to U.S. security and, consequently, met with resistance. This positioned the U.S. as a dominant power in the region, seeking to prevent any potential European encroachments on sovereign nations in the Americas.