Re: "all we would need to do is leave people alone"
My opinion of our role in the Middle East (because you asked) is none.
We have the means to be self-sufficient without ME oil, although strangely enough the left-Dems seem to prefer the dependence.
We have no obligation to defend Israel, although strangely enough the fundy Republicans seem to think otherwise.
We leave them the heck alone, so long as they are not attacking us. If/ when any nation attacks us, we declare war as the Constitution demands and we destroy their means to wage war. Ruthlessly and relentlessly. If a group attacks us, we focus our efforts on eliminating that groups ability to mount offensive action while being as careful as possible to 1) alienate that group from it's base and 2) eliminating it's ability to mount offensive action.
The bad guys learn real quick to let this sleeping dog lie.