Actually, it appears that he will always be clueless on foreign policy issues. It's bad enough he doesn't take the time to understand the issues and give them serious thought. Beyond that, he surrounds himself with advisors who half understand the issues and suggest ridiculous policies.
Given those two problems, it's not surprising that he would have a poor response to the embassy attack that killed our ambassadors. But I wasn't sure he was capable of the completely partisan and malicious response he gave.
I'll send you to Andrew Sullivan for the specifics. Andrew suggests that Romney's reaction is a sign that he is unfit to lead. I'd certainly agree. But it's not the first sign that he is unfit to lead our foreign policy. I doubt it will be the last. I just hope that with the economy being the biggest issue foreign policy doesn't get overlooked.