As ISIS Routs The Iraqi Army, Here's A Look At What The Jihadists Have In Their Arsenal

The T-55 tank series is a Soviet tank line that was produced from the end of World War II through the 1980s. It is estimated that ISIS has around 30 of these tanks, although it is unknown how well the organization can maintain and operate them.

Despite the tanks' age, they remain operational in up to 50 armies around the world. The tanks feature heavy armor, along with a 100-mm rifled gun and a secondary 7.62-mm machine gun.

The T-72 tank is the second-generation Soviet battle tank. The tank first entered production in 1971, and they're still rolling off the assembly line. ISIS has an estimated five to ten T-72 tanks, although it is unknown whether they will be able to keep the vehicles in working order.

The T-72 is heavily armored, and features a 125 mm main gun. It is also armed with a secondary machine gun and an antiaircraft gun.

ISIS acquired U.S.-built Humvees when it stormed Mosul. The U.S. had provided these same Humvees to the Iraqi Army. The vehicles allow for quick and effective movement across rough terrain.

The Humvee's heavy armor also protects forces against small-arms fire, as well as against collateral damage from indirect explosions. The vehicles offer little protection against land mines or buried IEDs.

Although ISIS does not have a weapon of choice, the AK-47 has become their standard assault rifle because of its low cost, durability, availability, and ease of use.

The AK-47 was originally developed by the Soviets, but quickly spread to other armies and irregular forces around the world. AK-47s are light weight, fairly effective, and remarkably easy to obtain.

The M79 Osa rocket launcher fires a 90 mm shell that is highly effective against tanks and fortified positions.

Investigative journalist Elliot Higgins (perhaps better known as Brown Moses) believes that these weapons originated in Croatia before being smuggled to Syrian rebels by Saudi Arabia. ISIS has used these rockets to devastating effect against the Iraqi Security Forces' armored vehicles.

This semi-automatic grenade launcher is lightweight and intended for infantry use.

Saudi Arabia smuggled Croatian RBG-6 launchers into Syria, according to Brown Moses. The grenade launchers eventually found their way into ISIS's hands, and are now being used in Iraq as well.

Iraq is awash with RPG-7s, with the Iraqi Security Forces, the Kurdish Peshmerga, and ISIS all using the rocket propelled grenades in their arsenal.

RPG-7s are highly portable unguided shoulder-launched antitank weapons. These systems are durable and relatively low cost. They're also fairly simple to use.

The grenades can reach distances of up to 920 meters, although at greater range the projectile may self-destruct without hitting a target.

The M198 howitzer is a medium-sized artillery piece that must be towed between locations. It was developed for service within the U.S. Army after World War II.

The M198 can fire rounds upwards of 14 miles. This howitzer can launch a variety of munitions, including high explosives, rocket-assisted projectiles, and white phosphorus. ISIS likely captured howitzers from the Iraqi Army after they fled their bases.

The Type 59-1 is a Chinese copy of the Soviet M-46 M1954 towed field gun. The M-46 was first produced by the Soviets in 1954. At one point, the M-46 had the longest range of any artillery system in the world with a 17-mile maximum firing range.

The Type 59-1 is a licensed Chinese copy of the significantly lighter M-46. Both the Syrian and Iraqi militaries made use of the Type 59-1 field gun, providing numerous source points from which ISIS might have acquired this weapon.

The ZU-23-2 is a Soviet anti-aircraft autocannon which was produced from 1960 to the present day. This autocannon fires 23 mm rounds at a rate of 400 rounds per minute.

The ZU-23-2 can fire effectively at up to 2 miles, and it is designed to strike at low-flying targets as well as armored vehicles. This weapon has been used heavily so far in the Syrian Civil War, and it is also in the arsenal of the Iraqi Army.

The FIM-92 Stinger is a shoulder-fired infrared homing surface-to-air missile. It was originally designed by the U.S. and it entered service in 1981. These MANPADs are extremely dangerous and can effectively take down helicopters and aircraft.

FIM-92 Stingers require specialized maintenance and care. It is believed ISIS looted FIM-92s from Iraqi military bases.

The HJ-8 is an anti-tank missile which has been manufactured by China since the late 1980s. HJ-8s have an operational range of up to 6,000 meters and the system is partially based on the U.S. BGM-71 TOW missile.

HJ-8s are highly effective against armor, bunkers, and fortifications. The Free Syrian Army has been using these missiles to great success against the Syrian Arab Army since June 2013, although now ISIS has managed to incorporate these weapons into their arsenal.

The DShK 1938 is a Soviet heavy machine gun dating from 1938. It became the standard heavy machine gun of the Soviet Union during World War II, and it is still in production around the world.

The DShK has several uses, including as an anti-aircraft weapon and heavy infantry support weapon. It can fire 600 rounds per minute. The weapon can be mounted on cars for easy use and maneuverability. ISIS likely stole these machine guns from either the Syrian or Iraqi armies.

One of the most effective tools in ISIS's arsenal is their social media savviness. The group routinely churns out slick propaganda videos. It has an English-language outreach magazine, and puts out tweets hashtagged to trending events to achieve maximum exposure.

ISIS is armed for conventional warfare — and has years of experience waging asymmetrical campaigns in both Syria and Iraq. With such an arsenal at their disposal, and without a military willing to take them on, ISIS rule could become a settled fact of life in the heart of the Middle East.

Now check out the arsenal of the Kurdish Peshmerga»