Article updated 7/10/2017 to improve readability. Note that this article was originally written in 2015 and does not necessarily reflect developments since then.

American-made Tube-launched Optically-tracked Wire-guided (TOW) anti-tank guided missiles are a common sight in Syrian combat footage. The TOW missile is a large and powerful missile which requires a tripod and significant setup to fire. There are numerous videos of various rebel factions using TOWs to destroy Syrian Arab Army tanks, mostly T-55s, T-62s, and T-72s, of which the Syrian army possesses thousands.

Where do these TOW missiles come from? Some are from the United States, where the missile is made. The CIA has a program to train rebels with the system and has delivered an unknown number of TOW missiles to the Free Syrian Army and other moderate rebel groups to aid in their fight against Assad. One provision of the TOW supply program requires the rebels to return expended missile canisters in exchange for the new missiles, an attempt to prevent them from selling the TOWs. However, it seems that such efforts have not been entirely effective, as ISIS has gotten its hands on missiles intended for the rebels.

Like many weapon systems, the TOW is sold in large numbers to US-allied nations. Saudi Arabia, which recently purchased 13,000 TOW missiles from the US, has been instrumental in supplying the rebels. Recently, Saudi Arabia sent 500 TOW missiles to moderate Sunni rebel groups in Syria.

TOWs have reportedly been causing severe damage to the forces of Assad, including the destruction of over 15 armored vehicles during a single offensive. One of the Assad regime’s main assets is its mechanized army with Soviet equipment; the TOWs are crucial in countering the armor and eroding the regime’s advantage.

The value of the TOWs has been evident. Despite being pummeled by air strikes, Syrian rebels have been able to hold their ground against Assad’s recent offensives. FSA commanders attribute a portion of their successes to the TOW missiles, which they note can be used against vehicles as well as fortified positions and infantry formations.

What does the supply of TOWs to rebels mean for international relations and the conflict as a whole? For one, it points to the fact that the US government, the Saudis and indeed the majority of the West want Assad out and are willing to pay for it. The TOW missiles are most useful against armored vehicles, and the main operator of such vehicles is the Assad regime, so the supply of TOWs is evidently carried out in hopes of stunting the regime’s progress. ISIS has been in possession of armored vehicles since it overran Iraqi forces, but many of these have been destroyed by Operation Inherent Resolve. If the missiles were intended for use against ISIS infantry, vehicular IEDs, and fighting positions, the US and Saudis would probably supply cheaper, lower end missiles such as the AT4.

The injection of TOWs into the already saturated and chaotic Syrian battlefield demonstrates how the conflict is basically a proxy war. To many observers, the Soviet War in Afghanistan, where the CIA supplied Mujaheddin rebels with FIM-92 Stinger surface-to-air missiles, comes to mind as a parallel. The Stingers ended up being a thorn in the USSR’s side, taking out a significant if often exaggerated number of Soviet helicopters and ground attack craft. The story of TOWs in Syria appears to be similar. They are unlikely to be a game-changer, but they do offer the FSA a way to keep Assad’s armored forces on edge and stunt mechanized offensives. With current estimates generally citing losses of hundreds of Syrian vehicles to TOWs, it seems likely that the TOWs have been at least as effective against Assad’s forces as the Stinger was in Afghanistan, a much-needed boost for the FSA. However, with many of the missiles slipping into the hands of ISIS, there is certainly the potential for their deployment to backfire.