From today's NY Times coverage of Bush's press conference:
“If Iran had a nuclear weapon, it’d be a dangerous threat to world peace,” Mr. Bush said. “So I told people that if you’re interested in avoiding World War III, it seems like you ought to be interested in preventing them from having the knowledge necessary to make a nuclear weapon.”
If I am interpreting this correctly, Bush is suggesting that Iran should be attacked unless there are other means of "preventing them from having the knowledge necessary to make a nuclear weapon.”
This mere "knowledge" standard appears to be much lower than the standard supposedly applied to Iraq, where the Administration claimed that Saddam actually had WMD including an active nuclear program. It does not, for example, appear to require any sort of access to bomb-making materials.
I personally put the odds of an attack at greater than 50 percent. The only arguments I have heard against the likelihood of its happening are that (a) it would be insane, and (b) people (whether the public, the military, or Secretary Gates) wouldn't stand for it. I can't see that (a) matters to this crew, or that the public will stop it, or that the military can stop it given the principle of civilian control plus generals' craven careerism. I fear that means we're down to Secretary Gates.