You are so naive. You think politicians tell THE TRUTH? Good God.
There is a limited amount of resources on Earth for people to have. From that, either peaceful free trade will emerge, or an economic or violent struggle will ensue for those resources. Add to this the fact that a good percentage of leaders act on emotion rather than good sense, and let's face it, some of them aren't exactly sane either.
Do you think if we stayed completely out of foreign affaris altogether that we'd be better off? TRUST ME, we wouldn't. I can guarantee you we'd be just as bad off if not worse. Go read a history book instead of watching the [sarcasm]ultra un-biased[/sarcasm] CNN and FOX News before you go around thinking you can make foreign policy.
Do you have any basic grasp on human nature? If you leave people alone, they will not necessarily leave you alone (it's like that when it's with small groups, just imagine how it is with entire nations); given that, I don't think it is right for our leaders to entrust our welfare on the sanity and good will of other world leaders. That is a risk that a responsible chief executive will not take (but Clinton did anyhow, dumdeedum).