I'm not sure at this point. They both excel in this area. Bush seemed to be okay until 9/11 and then everyone was out to get us. I do remember Bush warning us what might happen if Iran ever got nukes. Well, it looks like they've got them. Obama is certainly using the same fear playbook as Bush which is why I often refer to him as Bush-III. They are definitely similar in many ways. We'll see how it all adds up when Obama leaves office in 2012 (unless the Republicans run a 'John Kerry' type politician against him).
Do you think that a brutal attack on the mainland U.S. that killed over 3000 people might make him a little cautious? Hmm.
We don't know that Iran has nukes yet. We don't know what they are going to do when they do. We know Israel is sufficiently concerned (rightly so) to be considering a pre-emptive strike.