Michael Walzer has an interesting counteragument in the New Republic:

Over much of those same decades, I have been arguing that our government should establish diplomatic relations with the Iranian zealots and tyrants. For liberals and leftists--opposition and nothing else; for state diplomats--handshakes and negotiation. The difference in the two roles is important. It doesn't mean that heads of state cannot defend political principles, but they also have other things to do. Right now, the most important task of the U.S. government with regard to Iran is not regime change. The most important task is to persuade or coerce the Iranian government to give up the effort to produce nuclear weapons. Doing that will require some mix of toughness and conciliation--and that necessary mix will still be necessary whoever actually won and whoever finally wins the Iranian election. What Obama says must be guided by what he has to do.


The rest of us are much freer. We can distinguish between the Iranian presidential candidates, all of whom were approved by the religious leadership, and their followers, many of whom have dissident views that the religious leaders would not approve. The dissidents are the people we should be supporting, whose stories we should be telling. And we should be talking to them about the kind of support they want and need. They and we are aiming at, and have every right to aim at, regime change. Organizations like Human Rights Watch and Amnesty International, though they can't acknowledge it, aim at regime change whenever they condemn the practices of tyrannical regimes; and so should union members and democrats of every sort, and religious moderates committed to freedom, and faculty members and students who believe in the integrity of the university. Regime change (it used to be called revolution) is our business, and we should embrace it.

http://www.tnr.com/politics/story.html?id=92bf92e8-242d-4924-9e5a-5be5cdb16715