When about a week ago Russian president publicly announced that Iran does not have nuclear ambitions, it looked like Russia and Iran had successfully solved the problems with fuel supply for the Busher nuclear power plant. Alexander Rumyantsev, who was on standby for more than a year, was promptly dispatched to Iran to sign the agreement.
It was expected that he and his Iranian counterpart will sign the document today. But they didn't. It's not clear yet what exactly had happened - one version is that Iran and Russia did not agree on the timing of spent fuel return, Iran reportedly asking Russia to be more flexible, but the problem seems to be deeper and the situation more interesting than that.
Russia, quite unexpectedly, found itself in an uncomfortable position in the Busher deal - it is Iran that is dictating the conditions now. The recent agreement with the EU apparently gives Iran leverage in dealing with Russia - theoretically it can now buy fuel in Europe (even though it's impractical). Then, there is a question of where Iran will buy its new nuclear power reactors after Busher is complete. There are a number of reasons why Iran would rather buy these from Europe, so Russia has all reasons to be nervous and show "more flexibility".
So, the question is still moot - who will be the first to sign the fuel agreement with Iran - Russia or the EU? We may know the answer to this one very soon, maybe tomorrow, but the broader question will remain - will Russia be able to protect its position of a supplier of civilian nuclear technology to Iran?