Monroe Doctrine - Monroe Doctrine - Application and extension of the Monroe Doctrine: The Monroe Doctrine, in asserting unilateral U.S. protection over the entire Western Hemisphere, was a foreign policy that could not have been sustained militarily in 1823. Monroe and Adams were well aware of the need for the British fleet to deter potential aggressors in Latin America. Because the United States was not a major power at the time and because the Continental powers apparently had no serious intentions of recolonizing Latin America, Monroe’s policy statement (it was not known as the “Monroe Doctrine” for nearly 30 years) was largely ignored outside the United States. The United States did not invoke