The administration radicals believe it is time to invert what they see as another fundamental flaw in Bush policy tying US interests to reactionary Sunni regimes in the Arab world as a bulwark against Shia militancy. Tehran is militant, the new thinkers argue, but it is at least a rational state actor, with defined goals and interests, and therefore ultimately more amenable to cool discussion and engagement.
The more cautious wing warns against hasty interference in an opaque political system with all the unintended consequences that might entail.
The last thing we want, in my opinion, is to be on one side of the Shia-Sunni split, especially if that makes us de facto propper-uppers of Arab autocracy and drives the Iranian people into the arms of the mullahs. Persia remains the prize. And America is Persia's natural ally.