The crisis in Crimea cast a shadow Tuesday over another important international impasse: the talks in Vienna aimed at an agreement to curb Iran's nuclear capabilities.
The negotiations between Iran and six world powers came just hours after Russia annexed the Crimea, which had long historic Russian ties but which had been a district of Ukraine for about 60 years, following approval of the move in a Sunday referendum. Four of the other five powers (the United States, Britain, France and Germany) denounced the move and invoked sanctions against Russian officials.
While a spokesman for EU foreign-policy chief Catherine Ashton, who co-ordinates the nuclear talks, said it was business as usual during Tuesday's meetings, experts agree it is unlikely Russia will be going out of its way in the coming days to help Washington and the European Union put shackles on Iran, as long as it has shackles of its own.
"The U.S. and Russian positions on Iran's nuclear program already are pretty far apart," said Gerson Sher, an analyst at the Stimson Center in Washington. Now, with the current tensions over Crimea, Russia "will not exert itself" to close that gap.
"Russia already signalled that it might retaliate against Western sanctions," Mr. Sher said in an interview, "by refusing to allow inspectors from the U.S. to inspect its nuclear weapons facilities last week as required under the START treaty, as well as inspectors from the OSCE [Organization for Security and Co-operation in Europe] to do the same under a separate agreement.
"This is a pretty clear message that Russia is similarly going to press other countries – read Iran – to do the same," he concluded.
However, "it's not as if there has been a sudden deterioration in Russian support for an agreement," said Mark Heller, principal research associate at Israel's Institute for National Security Studies. "Even if there had been no Crimean annexation, Russia was never going to get tough with Iran, and Iran was not about to make the necessary adequate concessions on its own.
"What gets Iran to move are Western economic sanctions or a credible military threat," he said.
Speaking in an interview, Mr. Heller said that the United States has never really posed such a military threat to Iran, but it did invoke the sanctions that led to the current interim deal.
Under that agreement, reached in November, Tehran has shelved the highest level of uranium enrichment – a potential source of weapons-grade uranium – and obtained some relief from economic sanctions in return.
As far as the West is concerned, the six-month deal was intended to buy time for reaching a final settlement by July, under which Iran would agree to fully eliminate its capacity to devise a nuclear weapon any time soon. For its part, Iran has said it will never completely give up the means to enrich uranium.
"Russia was willing to go along with the interim arrangement," said Mr. Heller, "but it wasn't going to support such an ultimate agreement."
Even before the Ukraine crisis erupted, there were reports that Russian President Vladimir Putin was discussing a major deal with Tehran in which Moscow would get Iranian oil and Iran would receive money, goods and help in building new nuclear reactors – thus letting Iran escape the pressure of sanctions, it was thought.
Not so, said Mr. Heller.
"What Iran wants from the West – access to international financial institutions, to world markets and to advanced petroleum technology – it can't get from Russia," he said. "So it's still vulnerable to international sanctions."