Is democratic reform possible with the occupiers' tanks on the ground? What makes you think the U.S. even wants democracy in the Middle East? The neocons seemed more interested in having a free trade puppet state ally in the Middle East for purposes of resource extraction, which they termed "democracy" in a confusion (or deliberate lie) quite common in such discussions. Look how easily most of them gave up their noble goals, as soon as the Halliburton contracts were signed!
If the "neo-cons" didn't want democracy in Iraq, they've fucked up quite badly. Regardless of intent (which I think is quite clear, even though you describe "democracy" as a front for something else), the outcome has been democracy, and it didn't take too long (compared to other American post-war occupations, like Germany or Japan) to impliment.
Let's say that American power wanted a stable state for the puropse of resourse "extraction" (i.e. to buy Iraqi oil from Iraqis -- I don't expect that Iraqis will be too hostile to this new arrangement -- rather than the shady trades
some made with Saddam at the expense of Iraq) and that America's interest in Middle Eastern oil is as great as the EU's: if a democratic state is set up, which is happy to sell oil (because (Econ101) trade is an exchange that benefits both sides), what's the problem? Iraqis get to live in a state where they are not subject to the arbitrary brutality of the "Knight of Arabism", and you yanks get to role around in your beloved oil.
Also, this:
Is democratic reform possible with the occupiers' tanks on the ground?
Is democratic reform possible without the occupier's tanks on the ground? What do you think the Sunni insurgents will do? What do you think the Shia would do when the camel's back breaks -- as with the al-Askari Mosque bombing -- once again?
I don't see how you can make counterfactuals about Iran's current policies and recent history without this! It's like, "imagine the Cold War without the Soviet Union."
What I'm really trying to say is that even with a liberal regime in Iran, it is not certain that Iran would give up it attempts at nuclear power. Iran is a regional powerhouse and wants to be treated as such. Indeed, I think it should be treated as such, or certainly, it should be encouraged to come back in from the cold. I don't believe that Iranian nuclear power is reducible to a defense against American attack, although that concievably forms part of it.