The Arsenal

Russia deployed a range of fixed-wing aircraft to Hmeimim Air Base in Latakia beginning September 2015. The Su-24 Fencer (swing-wing bomber), Su-25 Frogfoot (ground attack), and Su-34 Fullback (strike fighter) formed the core of Russia's strike package. The Su-34's first combat deployment was in Syria. These aircraft delivered precision-guided munitions, unguided 'dumb bombs,' and cluster munitions on targets across Syria. Russia's air campaign was notable for its targeting of hospitals, markets, and civilian infrastructure in rebel-held areas — what OHCHR investigators described as deliberate targeting of civilian objects to break opposition morale.

The Soviet-designed T-72, in various Syrian and Russian variants, was the Syrian Arab Army's primary armored vehicle throughout the conflict. Assad's forces used T-72s to shell urban neighborhoods, breach rebel defensive lines, and conduct the armored operations that ultimately recaptured Homs, Aleppo, and other major cities. The tank was also used by rebel groups who captured examples from government forces and by ISIS, which seized hundreds of tanks from the Iraqi Army. T-72 losses were substantial; both government and rebel forces resorted to improvised anti-tank warfare.

The barrel bomb became the most recognizable and reviled weapon of the Syrian war. These improvised explosive devices — typically oil drums or fuel tanks packed with explosives, metal fragments, and sometimes chlorine gas — were rolled out of Syrian military helicopters (primarily Mi-8/Mi-17) over rebel-held areas. Because they were dropped from altitude and had no guidance system, they were inherently indiscriminate; they could not be aimed at military targets and landed throughout civilian neighborhoods. The SNHR documented over 80,000 barrel bomb attacks between 2012 and 2019. Barrel bombs became synonymous with the deliberate targeting of civilian populations and are widely considered to constitute a crime against humanity.

Syria possessed one of the Middle East's largest chemical weapons programs, including sarin, VX, and mustard gas. The OPCW documented over 300 chemical weapons incidents in Syria, the majority attributed to the Assad government. Sarin was used in the most lethal attacks: Ghouta (August 2013, ~1,400 dead) and Khan Shaykhun (April 2017, 83 dead). Chlorine, mixed with explosives in barrel bombs, was used as a chemical weapon hundreds of times. Despite Syria's 2013 accession to the Chemical Weapons Convention and the destruction of its declared stockpile, the OPCW repeatedly found evidence that Syria had retained and continued to use undeclared chemical agents.

The US-supplied BGM-71 TOW (Tube-launched, Optically tracked, Wire-guided) missile transformed rebel anti-armor capability beginning in 2014–2015, when the CIA's 'Timber Sycamore' program began delivering them to vetted Syrian rebel groups. The TOW gave rebel units the ability to destroy government T-72 tanks at ranges up to 3,750 meters, neutralizing Assad's armored advantage in open terrain. Rebel groups filmed hundreds of TOW strikes and posted them to YouTube, creating a remarkable public record of the weapon's use. The TOW program was the most significant direct US military contribution to the anti-Assad rebels; it was terminated in 2017 as the US pivoted to prioritizing ISIS rather than Assad's removal.

The Soviet BM-21 Grad ('hail') is a truck-mounted system that fires salvos of 40 unguided 122mm rockets to ranges of up to 20 km. It was used extensively by the Syrian Arab Army to bombard rebel-held urban areas with high-volume, inaccurate fire — an inherently indiscriminate weapon when used against populated areas. Rebel forces also captured and used Grad systems. The BM-21 was responsible for extensive civilian casualties across Aleppo, Homs, Daraa, and other cities. Its use against urban areas constitutes a violation of International Humanitarian Law given its indiscriminate nature.

ISIS and other jihadist factions perfected the vehicle-borne IED as an offensive weapon, using trucks, cars, and armored vehicles packed with thousands of kilograms of explosives to breach defensive lines and kill large numbers of soldiers or civilians. ISIS developed standardized VBIED production lines in Iraq and Syria, with dedicated bomb-makers, drivers, and coordinators. In their most catastrophic form — fully armored bulldozers or military vehicles welded shut and packed with explosives — VBIEDs could breach fortified positions no conventional assault could reach. The technique was exported by ISIS to affiliates worldwide.

The PKM (a Soviet general-purpose machine gun) and DShK (a Soviet heavy machine gun firing 12.7mm rounds) were ubiquitous on all sides of the Syrian conflict. Mounted on Toyota Hilux 'technicals,' fixed in defensive positions, or used by infantry, these weapons defined the visual imagery of the Syrian war. The DShK in particular, mounted on vehicles and fired from rooftops, served as a makeshift anti-aircraft weapon against helicopters. Both weapons were widely available through looting of Syrian Army depots, purchases on black markets, and supplies from foreign patrons.

The US supplied M1 Abrams tanks to the Iraqi Army as part of post-war rebuilding efforts; when ISIS swept into Mosul in June 2014, the collapsing Iraqi forces abandoned dozens of Abrams tanks, along with hundreds of Humvees, artillery pieces, and weapons. ISIS captured at least 40 M1 Abrams tanks, though most were ultimately destroyed by coalition airstrikes or proved difficult to maintain without US logistical support. The spectacle of some of the world's most advanced tanks falling into jihadist hands became a symbol of the Iraq War's unintended consequences and the risk of equipping forces that might prove unreliable.

The Kurdish YPG/SDF, lacking access to conventional military suppliers in the early years of the conflict, improvised armored vehicles by welding steel plate onto agricultural tractors, pickup trucks, and civilian vehicles. These 'Mad Max' vehicles — sometimes equipped with welded-on turrets mounting PKM or DShK machine guns — became iconic images of the Kobani siege in 2014. As the SDF received US support, they acquired MRAPs, M113 APCs, and other military vehicles, but improvised armored vehicles remained in use throughout the anti-ISIS campaign. The YPG's ability to contest urban terrain against ISIS's conventional armor with improvised equipment demonstrated the enduring relevance of motivated irregular forces.

Russia's October 7, 2015 launch of 26 Kalibr cruise missiles from Caspian Sea warships — traveling over 1,500 km to strike targets in Syria — marked the first combat use of this weapon system and announced Russia's arrival as a long-range precision strike power. Putin personally timed the announcement for maximum impact, interrupting a press conference with German Chancellor Angela Merkel to report the launch. The Kalibr (comparable to the US Tomahawk) demonstrated Russia's ability to strike from unexpected directions and its possession of precision weapons previously associated only with the United States. The missiles' debut in Syria attracted immediate buyer interest and directly boosted Russian arms export revenue.

US Predator and Reaper drones conducted thousands of strikes in Syria from 2014 onward as part of Operation Inherent Resolve against ISIS. Armed with Hellfire missiles and GBU-12 bombs, these remotely piloted aircraft provided persistent surveillance and strike capability that conventional aircraft could not match. The Reaper drone that killed Qassem Soleimani at Baghdad airport in January 2020 had been operating in the Syrian-Iraqi theater. US drones also killed numerous ISIS leaders across eastern Syria and were instrumental in the final defeat of the territorial caliphate at Baghouz. The conflict also saw the first significant use of small commercial drones as weapons by ISIS, which modified DJI quadcopters to drop grenades.