Barbara Slavin writes: For months now, Russia has been a constructive member of the international consortium negotiating with Iran, often proposing creative fixes to technical hurdles.

But this week, just as the Senate Foreign Relations Committee was taking up sensitive Iran-related legislation, Russia announced that it was going forward with an old contract to sell Iran an air defense missile system that could make it less vulnerable to foreign attack.

The deal to supply the S-300 is not illegal under UN sanctions, which prohibit selling offensive heavy weaponry to Iran. The message the Kremlin is sending is that Russia is not willing to wait for the conclusion of negotiations on Iran’s nuclear program to lock in the benefits of resumed trade with the Islamic Republic.

It is unfortunate that the government of Vladimir Putin didn’t wait a few months longer. Critics of the Iran deal have been quick to pounce on the announcement as proof that the Barack Obama administration was somehow duped by Moscow and that the Iran framework so laboriously negotiated over the past 13 months is a “sucker’s deal.”

A more insightful way to read Russia’s act is to see it as a recognition of reality that the elaborate web of multilateral sanctions imposed on Iran over the past five years is unraveling and only an egregious Iranian effort to break out and build a nuclear weapon could arrest that momentum. [Continue reading…]