from a Washington Post article last week:
As he was preparing to take command, Fallon said that a war with Iran "isn't going to happen on my watch," according to retired Army Col. Patrick Lang.
Lang, a former analyst with the Defense Intelligence Agency, said in an interview that he asked Fallon how he would avoid such a conflict. "I have options, you know," Fallon responded, which Lang interpreted as implying Fallon would step down rather than follow orders he considers mistaken.
From the Post today: Top Military Commander Resigns
This may or may not mean war with Iran is imminent. An alternative explanation is that Esquire published an article last week that flattered Fallon at the expense of the administration. Fallon could have been canned because he committed the unforgivable (the only unforgivable in this administration)- making Bush look bad.
Either way, the canary in the coal mine just died.