Larison counters:
The Kremlin said that the Russian government wants the IAEA to investigate and that it will assist the investigation. This is not quite diplomatic boilerplate, but it is close. This is not, as Andrew says, a “breakthrough,” but a minimal statement expressing concern about reported violations of Security Council resolutions. At most the Russian government is saying that it has not officially decided how it will respond until the IAEA investigates. Russia has committed to nothing new, and it has not altered its stance on Iran sanctions, and there is little reason to think that this will change.
One of the things that worries me about trying to acquire Russian support for sanctions on Iran is that sanctioning Iran is already a counterproductive, foolish policy. It does not become a wiser policy when it has Russian backing. Significant Russian cooperation with a sanctions regime would make it more “successful” in that it would isolate Iran more fully, which would at least address part of the practical problem of imposing sanctions on Iran, but this would not lead to the result that sanctions advocates want. Most likely, China would pick up the slack and become even more heavily invested in trade with Iran than it has been. On the contrary, as opponents of sanctions keep saying, a tighter sanctions regime will harm internal political opposition to the regime, increase the political-military establishment’s hold on the economy and cause Iranians to rally behind their government in the face of outside hostility.
I take Daniel's points. But there was a question mark in my first post and I have continually expressed skepticism that Russia will come through in the end. As to his deeper point, I'm not fully persuaded that real sanctions, if actively backed by Russia or passively allowed by China, would be as counter-productive as Daniel implies. At the very least, I think exploring this option as thoroughly as possible is a good idea regardless. The worst that can happen is that Obama will have shown to the world the West's willingness to reach a peaceful solution - and the responsibility of Ahmadinejad if such a solution is impossible.
This is a tough call - as tough as Afghanistan. I lean toward doing all we can to avoid a military conflict in Iran and getting out of Afghanistan as responsibly as possible. But I'm open to alternative arguments in two excruciating dilemmas. I learned my lesson on Iraq - not to get locked onto a position without considering every possible angle. And one such angle is containing a nuclear-armed Iran rather than taking the huge risks of attempting to stop it through force.