Name one conflict since WWII where it was advantageous for us to fight another nation, or when we went to aid of an embattled ally? Every conflict since then has been motivated by resources acquisition, or to fight an illusionary communist threat that fell apart under its own weight more than from our constant intervention. The Gulf War was used to establish a U.S. military presence in the Middle East against the wishes of the Saudi people, and create a more favorable oil-trade situation. You could say Afghanistan was justified, but now it has become a launching pad to put pressure on Pakistan while we kill innocent civilians in their border regions on hunches that a terrorist is near by. Trade relationships need to be isolated from militaristic affairs, otherwise you have nations using force to create more favorable trade deals for themselves and their allies. China is our largest trade partner, I have yet to see U.S. troops help them suppress their people, or invade Tibet. In fact we actively defend Taiwan in direct opposition to China's desires. Your logic is flawed that militaristic aggression is advantageous in the development and continuation of healthy trade relationships. Isolationism is completely different that non-interventionism. Isolationism includes economic protectionism where the isolationist nation engages in unfair protectionist trade activities, or refuses to interact with other nations.