The M72 LAW is a portable one-shot 66 mm anti-tank weapon, designed in the United States by Talley Defense Systems, produced by Nammo Raufoss AS in Norway. The LAW replaced the bazooka as the United States Army's primary anti-tank weapon after the Korean War. It was intended that it would be replaced in service by the FGR-17 Viper (which would also replace the FGM-77 Dragon), but this program was cancelled and the M136 AT4 was introduced in its place.
Although generally thought of as a Vietnam War era weapon which has been superseded by more powerful and sophisticated designs such as the SMAW and AT4, the M72 LAW has found a new lease of life in the ongoing (2006) operations in Iraq by the US Army and Afghanistan by the Canadian Army. The low cost and light weight of the LAW, combined with a proliferation of lightly-armored targets, make it ideal for the type of urban combat seen in Iraq and Afghanistan.
The AT4 (or AT-4) is a portable one-shot anti-tank weapon built in Sweden by Saab Bofors Dynamics (previously Bofors Anti Armour Systems). In the U.S. and NATO inventory it replaces the M72 LAW. Saab has had considerable sales success with the AT4, making it one of the most common light anti-tank weapons in the world. It is intended to give infantry units a means to destroy or disable armored vehicles and fortifications they may encounter (though it is not generally sufficient to defeat a modern main battle tank). The launcher and projectile are manufactured, pre-packed, and issued as a single unit of ammunition (rather than a weapon system), with the launcher discarded after use.
The Javelin is a manportable, antitank system developed for the U.S. Army and U.S. Marine Corps (USMC). Highly lethal against tanks with conventional and reactive armor, Javelin will provide a medium antitank capability to the infantry, scouts, and combat engineers. A simple-to-operate, economically maintained, rugged and reliable infantry system, Javelin has two major components: a reusable Command Launch Unit (CLU) and a missile sealed in a disposable Launch Tube Assembly. The CLU incorporates an integrated day/night sight and provides target engagement capability in adverse weather and countermeasure environments. The launch unit also may be used in the stand-alone mode for battlefield surveillance and target detection.