Syrian air defenses attempted to intercept an attack west of Damascus on Tuesday. It fired an array of missiles at targets, and Syrian state media claimed it scored interceptions. Like previous claims, this one is likely false or only partially accurate. Syrian air defense consists of multiple layers of weapons systems, including the S-300, which Russia supplied in early October.The following is a list of the different systems Syria has and evidence as to which may have been used recently. Syrian air defense consists of Russian systems of surface-to-air missiles, some of them antiquated. SA-22An anti-aircraft missile system, it is also called the Pantsir S-1 and is used to protect military bases and other targets. It is supposed to be used for low-altitude threats and has a mobile version that can be mounted on a truck. Designed in Russia, it has been around since the mid-1990s. In 2000, the UAE purchased 50 units of the system and Syria bought $900 million worth of the system in 2007. Deliveries came in 2008, three years before the civil war broke out. The system can threaten aircraft over the Golan. Iran supported the Syrian purchase. It reportedly downed a Turkish reconnaissance plane in 2012 and has been used to defend Syrian airspace over the years. One of its batteries was destroyed in May 2018 after Iran fired a salvo of rockets at Israel from Syria. It has a range of only 20 km.S-125Also called the SA-3, this antiquated system was developed in the 1950s and was supposed to deal with medium-altitude threats as part of a layered system that would include the S-200 and other defenses. It has a range of around 15 km. and is paired with a radar system. Syrian Defense Ministry representatives attended a training session in Russia to improve their air defense in 2011. At the time, before the Syrian civil war broke out, Syria was alleged to have the S-200, S-125 and Buk. It was also seeking to modernize its air defense with supplies of two S-6 Tunguska air defense missile systems and 18 of the Buk-M2E as well as 36 Pantsir S-1. In this context, the S-125 was one of many systems the Syrians were attempting to use in their inventory. Russia has built other versions of it, but Syria’s air defense has not found the system to be very effective.Buk missile systemDesigned originally in the 1970s, the system is supposed to confront cruise missiles, small slow-moving aircraft, drones and smart bombs. Also called the SA-17 Grizzly, Syria acquired a mobile version of it called the Buk-M2. The mobile missile launcher has four missiles that are connected to a target-acquisition radar and a battle-management station. Hezbollah allegedly sought to acquire this system in 2015. The more advanced version has a range of up to 150 km. At least one of the systems was destroyed in May.S-200Also known as the SA-5 Gammon, it is designed to confront high-altitude targets and has a range of 150 km., with more modern variants extending that to 300km. With a 200-kg. warhead, it is bigger than those of the Buk (70 kg.) and the S-125 (60 kg.). Syria has attempted to use the S-200 to defend itself against airstrikes. In March 2017, an S-200 missile reportedly carrying a 200-kg. warhead was headed for the Jordan Valley when Israel intercepted it with an Arrow missile. In another case, an S-200 followed an Israeli F-16 back from Syria in February, causing the plane to crash. Syrian air defense is deployed extensively around Damascus, Homs and around the T-4 air base, in strategic locations. One report says that there are two Panstir S-1 systems at T-4, where Iranian forces have allegedly been based.TunguskaThe Tunguska air defense system consists of a tracked vehicle with machine guns and missiles. Also known as the SA-19 Grison, the Russian made system was designed in the 1970s. It can fire 5,000 rounds a minute and is supposed to be used against helicopters, low-flying aircraft and cruise missiles. It’s not entirely clear how active the system is in Syria, or if the Syrians use it. A 2017 article by Russia’s Sputnik news agency noted that if it had been active, it would have been able to defend against various attacks.S-300The system was developed in the late 1970s and has an older and a more modern version. The S-300 PM-2 was first rolled out in the mid-1990s. It has modern radar and a command center, as well as mobile vehicles for the missiles. It has a range of up to 200 km. The S-300 PM-2 is the more advanced system and Russia provided it to Syria in October. The system was reported operational in early November but has not been used by Syrian air defense yet, according to reports.THE LAYERS of air defense that Syria has should be able to confront some of the threats thrown at the regime. However, many of the systems are antiquated and cannot confront fifth generation airplanes, such as the F-35, nor have they proven to deal effectively with cruise missiles or other ordnance that can be fired from a long range. The full details of the shadow air war that has gone on over Syria in the last seven years are not fully clear. Israel has said it carried out attacks on 200 targets in the last two years, and in separate statements indicated that it struck another 100 targets in the years before that. But the types of munitions used have not been released, except in rare cases such as the F-16 that was destroyed returning from one mission. Russia must watch closely as its systems in Syrian hands do not prove to be effective. In one case, an S-200 destroyed a Russian IL-20. The slow moving IL-20 was an easy target at the time, but the S-200 was supposed to be targeting Israeli aircraft and failed in its mission. Russia also has its own more advanced S-400 system, radars and electronic warfare sites in northern Syria’s Latakia, but it has not used them. According to the Institute for the Study of War, Russia believes that to cover all of Syria, two battalions of S-400s and three to four battalions of S-300s would be necessary. With Syria holding on to its S-300, either concerned about using it or not being fully trained to use it, the regime’s air defense lacks the layered and modern systems that it needs to confront the kind of adversary it has been facing.