Wikipedia
Non-interventionism or non-intervention is a foreign policy that holds that political rulers should avoid alliances with other nations but still retain diplomacy and avoid all wars unless related to direct self-defense. An original more formal definition is that non-interventionism is a policy characterized by the absence of interference by a state or states in the external affairs of another state without its consent, or in its internal affairs with or without its consent.
This is based on the grounds that a state should not interfere in the internal politics of another state as well as the principles of state sovereignty and self-determination. A similar phrase is "strategic independence." Non-intervention is usually defined either as the determination by a nation to refrain from interfering in the affairs of other nations or those of its own political subdivisions or as the refusal or failure to intervene in the same.
Non-interventionism is not to be confused with isolationism, a political policy which sometimes carries with it laws that mandate a breaking of ties between the inhabitants of one political subdivision and another.
Historical examples of supporters of non-interventionism are US Presidents George Washington and Thomas Jefferson, who both favored non-intervention in European wars. Other proponents include United States Senator Robert A. Taft and United States Representative Ron Paul.
Non-interventionism is distinct from and often confused with isolationism. Proponents of isolationism differ from proponents of non-interventionism through their advocacy of economic nationalism (called also protectionism) and immigration reduction. Non-interventionism is a policy in government only and thus does not exclude non-governmental intervention by organizations such as Amnesty International.