Moscow is confirming that it has delivered SA-15 short-range surface-to-air missiles to Iran, part of a deal that was signed more than a year ago. The SA-15 (which the Russians refer to as the TOR-M1) is designed to bolster Tehran's point defenses, offering improved protection of high-value targets, including its nuclear facilities.
We've written extensively on the TOR-M1 deal in the past. While it is a high-tech system, it is not sufficient to deter U.S. or Israeli strikes against Iran. In fact, the U.S. (and probably, Israel) have a detailed understanding of the system and its capabilities, meaning that we already have measures for dealing with it, including pre-emptive cruise missile attacks, anti-radiation missiles (than home on the system's radar emissions), jamming programs, and simple avoidance of known SA-15 positions. Deployment of the system (coupled with dedicated denial and deception measures, including frequent movement) will complicate potential strikes on Iran, but it won't prevent them.
One interesting note in the Russian announcement is Moscow's stated willingness to sell more "defensive" systems to Tehran. As we've noted before, the Iranian air defense system is full of aging equipment and has obvious gaps in coverage that can be exploited by potential foes. One partial solution to those problems is the acquisition of a state-of-the-art, long-range SAM system, such as the SA-20. There have been rumors that Moscow and Tehran have discussed an SA-20 deal before. Today's comment may be a hint that such discussions are underway again, or will resume in the near future. At roughly $300 million a battery, the SA-20 is expensive, but it would go a long way toward solving some of the coverage problems inherent in Iran's air defense system, particularly against low-altitude, low-RCS targets like cruise missiles.