Final answer:
The Roosevelt Corollary to the Monroe Doctrine extended the U.S. role in the Western Hemisphere by asserting the right to intervene as an international police power to maintain order and prevent European influence.
Step-by-step explanation:
The Roosevelt Corollary to the Monroe Doctrine asserted the United States' right to interfere in the economic matters of other nations in the Americas. The Monroe Doctrine, introduced in 1823, established that European nations should refrain from intervening in the Western Hemisphere, positioning the U.S. as the protector of this region. President Theodore Roosevelt extended this doctrine with his 1904 Corollary, which he justified as necessary to maintain order and prevent economic instability that might attract European intervention.
This new policy of acting as an "international police power" in the Western Hemisphere was used to justify U.S. interventions that protected American corporate interests and ensured debt repayment to U.S. and European banks, thus preventing European entanglements in Latin American affairs.