The Roosevelt Corollary was a policy that established the right of the United States to act as a policeman in the Western Hemisphere.
It's an addition to Monroe's doctrine which claimed the right for the United States to intervene in cases when some certain nation created some wrong doing. It was pointed mostly towards the countries in Latin America. Roosevelt believed that the States should function as a protector of the Western Hemisphere.
Further Explanation:
Roosevelt believed United States should interfere in the problems between European and Latin America's states
Policy of not allowing European states to put there hands on Latin America
Addition on Monroe's doctrine
United States have a right to exercise their military power
