Aviation Week is reporting that Russia has already begun deliveries of the S-300 air defense system to Iran.

Moscow’s confirmation comes just days after U.S. defense officials reported that Tehran had signed an agreement to acquire the state-of-the-art missile system. At the time, it was suggested that Russia would ship the air defense hardware through Belarus, to avoid direct participation in the deal.

But, when questioned by the RIA-Novosti news agency, a Russian official practically bragged about the sale, saying that weapons deliveries to Iran “have a positive impact on regional stability.”

While U.S. intelligence has not confirmed the S-300’s arrival in Iran, there is little reason to doubt the Aviation Week account. The mobile system is air-transportable, and Russia has enough heavy lift assets to move a full battery (or entire battalion’s worth of equipment) to Iran, in relatively short order.

Shipments of the S-300 to other export clients–including Vietnam and China–have been handled by ship, through ports on the Black Sea. Air transport is not only much faster, it avoids potential political problems associated with military shipments through the Black Sea and Suez Canal, or the Caspian Sea. There was some speculation that Israel might attempt to interdict SAM shipments made by ship.

Iran is apparently receiving the S-300PMU1 Favorit, one of the newest models of the air defense system. Capable of engaging multiple targets simultaneously, the S-300 version being acquired by Tehran can intercept aircraft at ranges up to 200km, and ballistic missiles at a distance of 40km. The S-300’s overall capabilities are roughly akin to those of the U.S. Patriot system.

As we’ve noted in previous posts, the S-300 (NATO designation: SA-20) fills a critical gap in the Iranian air defense system. Until its acquisition of the SA-15 last year, Tehran relied on a collection of aging Russian, Chinese and U.S. equipment to defend its airspace. The only “long-range” SAM currently in Tehran’s inventory, the Russian-built SA-5, has no capability against tactical aircraft or ballistic missiles. Correcting those deficiencies (and others), the S-300 represents a quantum leap in Iranian air defense capabilities.

The system’s rush delivery to Tehran is clearly aimed at deterring an Israeli or U.S. air strike. And, in that regard, the S-300 is something of a game-changer, forcing changes in potential tactics and strike plans. Operating in airspace defended by the system carries considerable risks; it’s a threat that must be considered in any future campaigns against Iran.

But Iran’s new SAM system is hardly invulnerable. With precise intelligence, optimal planning and tactical execution, the S-300 menace can be neutralized. Still, achieving that goal will be difficult. Locating mobile SAMs requires more ISR assets, and taking them out dictates a greater allocation of standoff weapons and aircraft dedicated to the SEAD (suppression of enemy air defense mission.

Such requirements would (seemingly) pose the greatest challenge for the Israelis, who have a more limited ability to project airpower over long distances, and sustain air attacks against those targets. However, it would be a grave mistake for the Iranians–or their Russian suppliers–to underestimate the IAF.

During last year’s strike on that Syrian nuclear facility, the Israeli strike package flew unmolested to the target and back again. By some accounts, the Syrians never knew that Israeli jets were in their airspace until the bombs demolished that nuclear reactor. More embarrassing, Damascus’s integrated air defense system never engaged the IAF formation.

Achieving that level of surprise–and success–has long been a hallmark of the Israeli Air Force. It’s also an indication of how well the IAF knows its adversaries and their vulnerabilities. There have been reports that Israel used information operations to blind the Syrian IADS, specifically an attack on the computers and nodes that control the air defense system.

Both Israel and the United States are capable of a similar effort against Iran. Once operational, the S-300 batterys in Iran will be tied into the country’s air defense network, a system that has long been vulnerable to saturation, jamming and confusion. Without reliable information from early warning radars and air defense centers, the S-300 will be forced into an autonomous mode.

While most surface-to-air missiles are capable of operating on their own, they are less efficient and more susceptible to interdiction efforts. Isolating a SAM battery is often the first step in killing it.