I don't think you'd ever get complete isolationism, because the US is fully tied into the global market, and it can't let threats to vital resources go unanswered... and oil is the most vital. The only way you'd get the US to be uninterested in what goes on in the ME is to have another huge source of oil pop up somewhere else. If that happened, then you would indeed see the US pull lock, stock, and barrel out of there. You might see us pull out of Diego Garcia and Europe as well, if we're not worrying about the ME... which also does away with 9-11, Iraq, Afghanistan, etc.
Of course, if the US does retreat into a sort of political isolationism, then instead of being pilloried by the international community for interventionism, we'd be pilloried by the international community for not helping out around the world where it needs it. Basically, you can't win...