bornahorn,
The bottom line is that 2003 and folks who agree with him on this think the entire problem is our fault and that if we just got out of the Middle East and didn't defend Israel, everything would be fine (as if the Middle East was a peaceful place before we came along). They're so sure of it that they're willing to put all of their eggs in that basket. It's not possible for them to be wrong or even less than 100 percent right. Accordingly, they have no contingency plan at all in the event that they're not perfectly right, or if they do, they're not willing to discuss it. That's really the problem I have with the Ron Paul mentality on foreign policy. If you ask them what happens if they end up being wrong, you hear nothing but crickets chirping. They either say it's impossible for them to be wrong, redirect the question to something else, or just ignore the question.
If Israel was threatened or even actually attacked, they would probably say we shouldn't meddle in the situation and let the chips fall where they may. However, don't expect to get any of them to actually answer you on the hypothetical question. Iran would have to actually attack Israel before they'll answer the question.