Nonintervention or non-interventionism is a foreign policy which holds that political rulers should avoid alliances with other nations, but still retain diplomacy, and avoid all wars not related to direct self-defense. This is based on the grounds that a state should not interfere in the internal politics of another state, based upon the principles of state sovereignty and self-determination. A similar phrase is "strategic independence". Historical examples of supporters of non-interventionism are US Presidents George Washington and Thomas Jefferson, who both favored nonintervention in European Wars while maintaining free trade. Other proponents include United States Senator Robert Taft and United States Congressman Ron Paul.