So the New York Times reports today: "Russia has informed Iran that it will withhold nuclear fuel for Iran's nearly completed Bushehr power plant unless Iran suspends its uranium enrichment as demanded by the United Nations Security Council." Smackdown! Or maybe not. According to Bloomberg, Russia is now denying that it ever issued such an ultimatum, and is really only withholding the fuel because of a dispute over late payments (which would make perfect sense). If anyone wants to parse all the various statements here, feel free. This bit from the Times piece, though, was intriguing:
The Russian Atomic Energy Agency, or Rosatom, is eager to become a major player in the global nuclear energy market. As Security Council action against Iran has gained momentum and Iran's isolation increases, involvement with the Bushehr project may detract from Rosatom's reputation.
That seems like as plausible a reason as any for Russia to decide to confront Iran over the latter's enrichment program. Although if the denials to Bloomberg are true, it hasn't really reached that point yet.