Rumors concerning the S-300 have been on-again, off-again for years, but RIA Novosti reported that “Moscow has earlier met its obligations on supplying Tor-M1 systems to Iran and is currently implementing a contract to deliver S-300 systems.” The news agency also quoted Alexander Fomin, deputy head of the federal agency in charge of Russia’s military exports, as saying, “Russia’s military and technical cooperation with Iran has a positive impact on stability in this region.” Fomin added, “We have developed, are developing and will continue to develop this cooperation further. The region’s security to a large extent depends on this.” The article follows reports that an Israeli military delegation traveled to Moscow in recent days to try to dissuade Russia from delivering the weapons.

The importance of the S-300 — specifically the more modern PMU series — is that it would increase the difficulty of air attacks against Iran. The first stage of any attack is the suppression of enemy air defenses (SEAD). Except in the case of a sudden attack on a single target, SEAD is a precursor to any sustained air campaign, and given the relatively large number of Iranian nuclear sites, taking out those facilities would involve such an extended campaign. Having to suppress a series of S-300PMU batteries would extend substantially the number of sorties and the time required for this phase of the attack.

This would affect both Israeli and American calculations. Given the size of Israel’s air force and the distances involved, the additional attrition and time involved in the SEAD phase might well extend an Iran campaign beyond Israel’s capabilities. It is not clear whether the S-300 would take a conventional Israeli option off the table, but it certainly would make things more difficult should Israel decide to carry out the attack. The United States would have greater ability to make such a move, but Washington’s recent agreement with Baghdad stipulates that Iraq cannot be used as a base for attacks against neighboring countries. And the Turks do not want the Americans to attack Iran from their soil. Put simply, the introduction of the S-300 would push the difficulty of a non-nuclear attack to the limit for Israel and complicate matters for the United States.

Of course, this is what the Russians mean to do. We do not know what happened during the conversations U.S. Sen. Richard Lugar and former secretary of state Henry Kissinger held in Moscow in recent days, but the Russians clearly have decided to turn up the heat. Russia has shifted its position from not wanting to increase tensions through the sale of the S-300 to seeing the sale as stabilizing the region — which it would do at the expense of potentially reducing U.S. and Israeli options.

Moscow does not want the Iranians to have nuclear weapons, but the Russian view is that the Iranians are rather far away from developing them. The more important issue for Russia is forcing the Americans to recognize Moscow’s sphere of influence in the former Soviet Union - by withdrawing their support for Ukraine, Georgia and other countries in the region. For the United States, the Iranian issue has been a priority. The Russians have just made it clear that if the Americans do not give them what they want, they will complicate U.S. policy on Iran as much as they can.

Obama takes office in about a month. It is not clear what point the Russians have reached in actually transferring S-300s, but in a month’s time, they could be either on the verge of transferring or already in the process. That means Obama will be forced to respond very quickly to Russia’s action. His options include forcing some sort of confrontation with the Russians; doing nothing, and thus accepting Russia’s intrusion into a core American interest; moving rapidly to deal with Iran; or (and we doubt intensely that he would choose this option) moving to strike Iran before the S-300s become operational.

It may be that American defense analysts will conclude that the S-300 does not significantly affect the balance of power in the region. But the S-300 does affect the psychological balance. The Iranians will feel that they are far less isolated than the Americans want them to feel, and that change alone will have a significant effect. Whether viewed militarily or politically, Russia’s action matters.

This is not a situation on the scale of the Cuban missile crisis, but it is a significant challenge to American interests on Russia’s part. If Obama does nothing, he will be seen as weak; if he gives the Russians what they want, he will be seen as an appeaser. And if he moves toward a major crisis or even military action, he will be seen as overly aggressive. With this move, Russia’s aim was to push Obama into a corner and say, in Russian, “Welcome to the big leagues.”