I'm a bit of an isolationist. If we grew to feed ourselves, and drilled to fuel ourselves, and entertained only ourselves, and only spent what we had to spend (our national debt at this moment is...

, and stopped exporting our culture, we'd be better off. etc etc etc.
Isolationism is a foreign policy which combines a non-interventionist military policy and a political policy of economic nationalism (protectionism). In other words, it asserts both of the following:
1. Non-interventionism – Political rulers should avoid entangling alliances with other nations and avoid all wars not related to direct territorial self-defense.
2. Protectionism – There should be legal barriers to control trade and cultural exchange with people in other states.
Isolationism is not to be confused with the non-interventionist philosophy and foreign policy of the libertarian world view, which espouses unrestricted free trade and freedom of travel for individuals to all countries. This "libertarian isolationist" view is best defined as a policy of nonparticipation in foreign political relations, but free trade and affability to all people.
I'm sure the national debt has risen a few hundred thousand by now.