Because of last night/this morning's news: the BGM-71 TOW Missile

What is it?

The BGM-71 TOW is a Tube launched Optically Wire guided missile system that falls into the category of Anti-Tank Guided Missile (ATGM). Identical to the TOW missile system is the Iranian Toophan missile, a reverse engineered TOW missile.

What are the parts?

The TOW missile launcher is a sled, that holds the inserted missile cartridge, the tripod that supports the sled, a guidance/power unit, and a set of 1-3 different optics used to watched the missile as it fires.

How does it work?

When the user inserts a missile into the sled, they then search for their target. Once a target is found and the missile launched, the missile trails a wire connected to the launcher behind the flight of the missile. The user is able to send commands to the missile over this wire, which gives the user the ability to adjust the missile for a moving target or to fly a more random path to avoid countermeasures. If this wire is severed the missile goes erratic and flies off in a random direction.

Why is it special?

As a dated platform that has faced being pulled from US arsenals many times, the TOW is not particularly special. It's just hardy, we have lots of them, and many countries buy them from the US. There are quite a few variants of the missile, and the current version the US uses is mostly the "E" and "F" variants (capable of top down attacks, and designed to defeat reactive armor), while the rebels are receiving the "A" and "B" variants (plain warhead). The TOW missile has exceptional range, roughly 4200 meters, and the optics allow it to be tracked all the way to the this range.

Recently declassified CIA reports show that penetration is roughly 430mm of armor for the basic TOW (what the rebels have) and 630mm for the improved TOW. It's not a particularly fast weapon, at roughly 300m per second, and can be visually tracked.

What else is like it in Syria?

Syria is one of the most anti-tank weapon rich environments on the face of the earth right now. In addition to the TOW, the Syrian Arab Army stocked massive supplies of similar wire-guided systems like the Konkurs or the smaller Fagot.

Bigger and more powerful systems like the Kornet have ranges up to 5,500m and carry a large warhead than either the Konkurs or the TOW, accounting for one of the only Russian bloc ATGMs that can routinely knock out an M-1 Abrams tank.

Similarly, the Chinese HJ-8 "Red Arrow" surfaces in Syria quite regularly and boasts a similar performance to the TOW.

Conclusion

The TOW missile system is a devastating anti-tank missile system, and the complicity of the US in supplying it from Saudi arsenals to "vetted" rebel groups is well known. But the TOW missile system is hardly any more of a "game-changer" than the existing (and far more plentiful) anti-tank weapon systems in Syria at present.

It's worth noting that the primary armor of the Syrian Arab Army is 1950s era T-55 "monkey model" tanks that have received some upgrades. These tanks are routinely destroyed or made immobile by weapons as simple as RPG-7s and IEDs. What makes the ATGM (all variants) so important is the standoff distance it gives. Being able to hit a tank or artillery piece (or aircraft as recently shown) at several kilometers away greatly increases your chances of surviving the encounter.

Edit: correction, Kornet EM model not fielded in Syria.