A terrible moment of decision is rapidly approaching where the outcome of the revolution in Iran will be determined. It has been said — and I largely agree — that the fate of Iran is for the Iranians and there is little that the United States can do. But little is not nothing and should the prospects of the dissidents begin to dim, that little will become much greater in stature. The Obama administration faces a dilemma here — a real dilemma that leaders in the real world face (discouragingly, one must add this last qualification because on the right there is no acknowledgement that our means are limited and our objectives trade-off here). The United States presently has two objectives with respect to Iran:

1. We would like to do reach an agreement regarding their nuclear program. The best situation would be that they abandon enrichment altogether, but one where they pursued a nuclear energy program, but verifiably ruled out weaponizing their nuclear material would suffice.

2. We would like to see a liberalized, less theocratic Iran. This is in part the traditional, principled position of United States, but it is also practical. A liberal democratic Iran will have a moderating effect on the rest of the Middle East, that epicenter of that global war on terrorism that we are fighting. And a liberal democratic Iran will presumably be less likely to provide support to militant elements in Palestine.

Presumably if two obtains, that will be progress toward one. A new, popular, modernizing régime looking to distinguish itself from its predecessor will be much more willing to deal with the United States and the Obama administration will have much less problem with its domestic constituents in dealing with such an Iran.

Alternately, no matter what the United States does, should President Ahmadinejad and Supreme Leader Khamenei succeeded in their bid to retain power, it will have become considerably more difficult for the President — any president for some time to come — to make progress on the nuclear issue. However, should the United States throw its weight behind the second objective and the Iranian dissidents fail, then the prospects for future progress on the nuclear issue will be even worse still than if we hadn’t — perhaps lost altogether. Not only will it be extremely difficult for any U.S. administration to deal with Iran, the Iranian government will return to the siege mentality of the 1980s and will perhaps — evidence that foreign powers will act to destroy the régime in hand — conclude that a nuclear deterrent is a necessity if the régime is to survive.

I have generally agreed with the position of restraint that the administration has taken. This is the Iranians’ struggle and strong words only make us feel puffed up — they do nothing for the Iranians. But that time may be coming to a close. Indications are that the Iranian government is moving with increasing forcefulness to suppress the dissidents. This is an effort that the government will win. Dissidents can route the police when it’s rocks versus batons. When the machine guns come out, it will be a different story. We cannot decide this conflict, but we can tilt the balance. The international community can make the government of Iranian aware that the consequences of suppressing its citizens extend beyond its own domestic politics. And perhaps — perhaps — this could bring them to the tipping point, or cause them to draw back from what they are about, or change the calculus of costs where a compromise solution becomes desirable.

But the United States and the Obama administration have to carefully weigh its principles and its objectives, its possibilities of success versus its consequences of failure. I’m not going to game it out here, but the range of options, consequences and rewards and probabilities attaching to each one should be fairly obvious. The nuclear issue is real and momentous and it would be terrible to sacrifice what possibility for progress exists chasing pie in the sky. But our principles are real too. It would be terrible for us to sacrifice them to cynical realpolitik over meager tactics when another world is possible. But not everything is possible and the future is uncertain. Judgment and luck are all that there is.