Russia has publicly announced that it is willing to sell Iran one of the world's most advanced air
Although a nuclear deal has yet to be reached with Iran and embargoes remain in place, Moscow has announced that it is ready to send the S-300 air defense system to Tehran.
If the deal goes through, Iran would have an extremely capable air defense system that could deter the threat of force against Iranian military facilities.
The following Reuters graphic depicts how the S-300 system works. In 2013, Russia delivered the defense system to Syria, which contributed to deterring Western intervention in the country.
Reuters Graphics
The S-300 is comprised of four road-mobile vehicle classes that work in tandem to detect and destroy aircraft. The missile launcher vehicles have a range of about 93 miles, can fire at multiple targets, and can down aircraft flying as high as 90,000 feet.
Iran's acquisition of S-300 systems would be "a complete game changer for all fourth-gen aircraft [like the F-15, F-16 and F/A-18]. That thing is a beast and you don't want to get near it," a senior US Marine Corps aviator told The Daily Beast.
If delivered, the systems would render Iran's air defenses nearly impenetrable against all but the most advanced US aircraft.
The S-300 "essentially makes Iran attack-proof by Israel and almost any country without fifth-gen [stealth fighter] capabilities. In other words, Iran, with the S-300, can continue to do what they want once those systems are in place without fear of attack from anyone save the US," a senior Air Force commander told The Daily Beast.
Basically, the existence of the S-300s would make any military action against Iran extremely difficult and costly - even for the US Military. As the systems are mobile, the US would have difficulty targeting the systems themselves while non-stealth jets would not be able to operate safely over Iran.
The delivery of the system would mitigate the threat of military action against Tehran in case of breaches in the nuclear agreement off the table.
Simultaneously, the weapons deal could lead to a greater axis of cooperation between Russia and Iran throughout the wider Middle East while providing Russia with some much needed money as sanctions continue to wreck the economy.
"The Kremlin is willing to treat the nuclear agreement as a done deal, at least when it comes to unlocking an $800m arms deal at a time when the Russian economy is hurting," Mark Galeotti, a New York University professor specializing on Russia, told Business Insider. "Besides which, it allows Moscow to prove itself a good friend."
Iran expects the missiles by the end of the year.