Yes, Vanessa, you are right that the Iranian elections are an argument against "U.S. interference" as a tool of democratization-if, by that, you mean U.S. military intervention. However, they are an excellent argument in favor of more peaceful forms U.S. democracy promotion, by which I mean radio programs like Radio Free Europe's Radio Farda , support for human rights websites (such as the excellent iranrights.org ) based outside the country and training and other kinds of support and training organized by the National Endowment for Democracy and similar groups. The point of such exercises is to help and assist indigenous movements, and they only work in places where the indigenous civil society is already strong (in Ukraine, for example, but not in Belarus). This is the sort of thing that the U.S. used to be rather good at, but lately has become less interested in; the decline began towards the end of the Bush administration, and has now, unfortunately, accelerated. The Obama administration has so far expressed little enthusiasm. Perhaps Iran will change their thinking.
One further point: Even the Bush administration didn't advocate "democracy at the point of a gun," as you put it; in fact the elections in both Afghanistan and Iraq, held under U.S. military supervision, were extremely popular with Afghans and Iraqis. Much less popular were the weak governments those elections subsequently produced. But the cause of their weakness was not democracy; quite the contrary.