Iran's decision to sue Russia in the International Court of Justice to try to force the sale of an air defense system deepens the crisis in the relationship between the two countries and underlines a shift in Russia's foreign policy priorities. But analysts say it does not necessarily spell the end of Russia-Iran cooperation.
The dispute centers on Russia's S-300 anti-aircraft missiles. Russia agreed to sell the weapons to Iran, but now says it cannot because of U.N. Security Council sanctions.
"What we're really seeing is an extraordinary downturn in Russo-Iran relations," said Russia specialist James Nixey. "They have been historically close, of course. But ultimately Russia views Iran as [being] unreliable as the West views Russia."
Nixey says Russia's leaders see relations with the West as so important that they are willing to offend Iran.
"I wouldn't read into this that Russia has discovered or re-discovered scruples, if you like," added Nixey. "I think the fact of the matter is Russia is still willing to go against U.N. sanctions on certain issues. It's done it before, and it's done it through third parties, which it may do again. But the fact of the matter is Russia is a 'realpolitik' power like no other. And it's weighed the pros and cons of the S-300 deal and it's decided at this point, it's just not worth going through with it."
That is bad news for Iran, says Gala Riani of the security firm IHS Jane's.
"It's viewed Russia throughout this period as very important ally, not just because of a close friendship, but really because Russia is still considered in many views as being one of the superpowers, an important power for Iran to have at its side," said Riani. "It's lost, to some degree, one of its closest allies in that Russia is now complying a lot more with the Western stance."
But Iran has not given up on relations with Russia. Iran's foreign minister visited Moscow in August, and Iran has welcomed Russia's approach to restarting the international dialogue over the Iranian nuclear program.
"Actually at the moment, Iran and Russian relations are just warming again," Riani noted. "Iranian officials are speaking more favorably about Russia as well, because it is not a relationship that they're willing to completely get rid of because they are still to some degree dependent on it."
Russia's decision to cancel the anti-aircraft weapons sale, and Iran's decision to sue, are clearly bad for their relationship, but there are already moves to repair it, and some analysts predict Russia may eventually try to find a way around the sanctions.