Re: "all we would need to do is leave people alone"
Sorry I missed this thread, but basically what the original post implies is the "Monroe Doctrine" or isolationism. This was fine for the US up until global communications and economy made it pretty difficult. The only nation I can think of that has successfully followed this path is Switzerland.
The problem here is that if you want to be a global leader, you are looked up to to help solve global issues. And, whether you personally agree with US foreign policy over the last 100 years or not, we have pretty much been the go to country in terms of helping the rest of the world....isolationism, even if it is specifically directed at a group, would fail in this modern era.
"Socialism is the philosophy of failure, the creed of ignorance and the gospel of envy. Its inherent virtue is the equal sharing of misery." - Winston Churchill