Non-Interventionism is the foreign policy of political rulers refraining from interfering in the affairs of foreign nations relations except for diplomacy and trade. It was the political belief of the Old Right, supporters of it today are known as Paleoconservative.
Non-Interventionism is different than Isolationism. In Isolationism that a country should have no relations with the rest of the world. While a non-interventionist believes that the U.S. should not interfere in conflicts between other nations or conflicts within nations.