Here's one proposal on what to do about Iran

Azar Nafisi, the author of Reading Lolita in Tehran, offers her prescription for the Iranian problem in the latest issue of TNR:

The fight for Iranian democracy is not simply a political one; in this respect, Iran is very much like communist Eastern Europe and apartheid South Africa....It is not just a struggle for political rights but also for the right of individual citizens to live the way they choose.

As to "who in the West will champion these existential rights on behalf of Iranians?" Nafisi thinks non-governmental-organizations may be the best option. As she writes:

No government--no matter how liberal--can devote itself only, or even primarily, to the defense of human rights and personal freedoms abroad, so we must rely on other actors to push the cause of liberty. I am speaking, of course, of nongovernmental organizations. What is needed is for human rights groups, activists, and journalists to take up the cause of the Iranian people. The secular journalist Faraj Sarkuhi, the former revolutionary and dissident Akbar Ganji, and the reformists Emadeddin Baghi and Ramin Jahanbegloo owe their freedom to a great degree to the efforts of organizations like PEN, Amnesty International, Human Rights Watch, and Reporters Without Borders, as well as to the attention of journalists throughout the world...

The progressive women who have staged two demonstrations since the start of Ahmadinejad's presidency are in the midst of a campaign to garner one million signatures demanding equality and justice for women in Iran. U.S. feminist groups should be doing far more to support them in their struggle.

Western governments, according to Nafisi, should not opt for the military solution, as she writes:

[T]he notion that Iran will be subdued into compliance with a handful of precision-guided missiles is as dangerous and fanciful as the belief that an invaded Iraq would serve as a model of enlightened democracy. Indeed, to attack Iran at this point would be to send a lifeline to the regime's most militaristic elements, which would use an attack as an excuse to quash all domestic dissent.

...The most important weapon in the U.S. arsenal is not its military might but its culture. Vigorously defending and promoting those values the United States was long thought to represent--freedom of expression, freedom of movement, freedom of conscience--will do a great deal more than any missile to neutralize Iranian radicals. And, though this wide-ranging task is probably beyond the capability of American politicians, it is not beyond the capability of America.