Final answer:
The Monroe Doctrine aimed to assert US power and influence in the Western Hemisphere and deter European colonization in the Americas.
Step-by-step explanation:
The primary focus of the Monroe Doctrine, which drove US foreign policy for roughly a century beginning in 1823, was to assert the United States’ power and influence in the Western Hemisphere and deter European colonization in the Americas. The objective of the doctrine was to prevent European countries from interfering in the affairs of newly independent Latin American countries and to establish the United States as the dominant power in the region.