Understanding Iran’s Deployment of the S-300 System

Iranian outlets this week reportedly revealed that components of Iran’s first Russian-made S-300 missile system were positioned around the Fordow fuel enrichment plant – an underground bunker which, until recently, was used for uranium enrichment. The long-range surface-to-air (SAM) system represents Iran’s newest and most advanced air-defense platform. Its deployment to Fordow sheds light on what the Islamic Republic believes requires defending.

The S-300 comes with varying abilities. Open-source information suggests that Iran has received the S-300PMU2 system, a modified version of the S-300PMU1 that Tehran initially bought in 2007. The PMU2 variant possesses radars that can detect upwards of 200 targets, while its missiles can down aircraft at 124 miles or ballistic missiles at 25 miles.

Placing the S-300 at Fordow is odd for several reasons, however. For one, Iranian authorities have lauded the facility for its “invulnerability” to attack because it was constructed under a mountain, too deep for most conventional bunker-buster bombs to penetrate. Why deploy the system there if it is invulnerable?

Moreover, pursuant to last summer’s nuclear deal (the Joint Comprehensive Plan of Action – JCPOA), Iran may “not conduct any uranium enrichment or any uranium enrichment related R&D” at the facility “for 15 years.” The JCPOA specifically requires the Fordow facility be transformed into a research center with international assistance. Thus, the deployment of the advanced Russian-made SAM to Fordow raises questions as to Tehran’s future nuclear intentions. After all, hardening this supposedly peaceful research facility with advanced missiles only diverts a limited capability away from logical targets an aggressor would strike, such as military bases, air strips, and other critical infrastructure.

Originally purchased in 2007, Iran’s S-300 order was blocked until April 2015 when the Kremlin lifted its self-imposed ban on the sale. The sale was likely revived due to progress over nuclear talks. The first components of the S-300 were delivered a year later when Tehran promptly paraded them before the public. Iran’s defense minister exclaimed in late August that Tehran had received the “full package of S-300 missile systems” from Moscow. Russian sources, however, say the delivery will not be complete until the end of the year. Regardless of when it was delivered, delivery of the SAM to Iran probably violated American statutes.

Meanwhile, Iran appears to be developing a domestic variant of the S-300, reportedly dubbed the Bavar-373. Iranian officials aim to have that platform come online by March 2017. It is likely that Iran will strive for some level of inter-operability between the domestic and Russian-made systems if it wants to more fully integrate these platforms.

While the current deployment pattern of Iran’s S-300 indicates that Tehran is hardening its defenses, the S-300 is a platform that Iran can quickly convert into a limited offensive tool (see: Making Sense of Iranian S-300s). The system is road mobile. Iran could thus position other batteries near the Persian Gulf, allowing the system to harass civilian air traffic or U.S. military aircraft patrols. In fact, the chief of Iran’s air defense forces implied this in June.

Iran might seem to have gained the upper hand at present, but that is disputable. For the S-300 to achieve maximum efficacy, its location must remain unknown. Knowing the approximate location gives potential adversaries a better chance to find, track, and destroy or disrupt the system with long-range standoff weapons before ever placing an aircraft at risk. Thus, by revealing the location of this system, Iran appears to be sending a message that despite the JCPOA it is keeping its nuclear options open.

Behnam Ben Taleblu is a senior Iran analyst at Foundation for Defense of Democracies, where Patrick Megahan is a research analyst focusing on military affairs. Mr. Megahan is also editor of the website, militaryedge.org