Presidential debate – Mortgages, taxes and Israel

Differences on many issues were clear in the debate tonight.
The three issues which stood out to me involved McCain’s plan to directly assist troubled mortgage holders, tax policy and Israel.
Question 13 on Israel was striking to me. If Israel was attacked, would the candidate commit troops to support Israel? McCain was clear that we would defend Israel. I am not sure what Obama would do based on his answer; he said he would not options off the table but he would also sit down with the Iranian president.
For readers who are keen on how the candidates stand toward Israel, I am interested in your reactions. I was surprised when Obama said this:

Now, it is true, though, that I believe that we should have direct talks — not just with our friends, but also with our enemies — to deliver a tough, direct message to Iran that, if you don’t change your behavior, then there will be dire consequences. If you do change your behavior, then it is possible for you to re-join the community of nations. Now, it may not work. But one of the things we’ve learned is, is that when we take that approach, whether it’s in North Korea or in Iran, then we have a better chance at better outcomes.

In the context of the question of whether Israel could count on US support, I think this answer might raise concerns that an Obama administration would not be a ready ally in the face of aggression toward Israel.