The M72 LAW (Light Anti-Tank Weapon, also referred to as the Light Anti-Armor Weapon or LAW) is a portable one-shot 66 mm unguided anti-tank weapon, designed in the United States by Paul V. Choate, Charles B. Weeks, and Frank A. Spinale et al while with the Hesse-Eastern Division of Norris Thermadore, 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. It can be compared with the better-known Soviet RPG-7 rocket propelled grenade, which uses a booster charge in addition to a rocket.

The weapon consists of a rocket packed inside of a launcher made up of two tubes, one inside the other. While closed, the outer assembly acts as a watertight container for the rocket and the percussion cap-type firing mechanism that activates the rocket. The outer tube contains the trigger, the arming handle, front and rear sights, and the rear cover. The inner tube contains the channel assembly which houses the firing pin assembly, including the detent lever. When extended, the inner tube telescopes outward toward the rear, guided by the channel assembly which rides in an alignment slot in the outer tube's trigger housing assembly. This causes the detent lever to move under the trigger assembly in the outer tube, both locking the inner tube in the extended position and cocking the weapon. Once armed, the weapon is no longer watertight even if the launcher is collapsed into its original configuration.

When fired, the propellant in the rocket motor completely combusts before leaving the tip of the launcher, producing gases around 1,400 °F (760 °C). The rocket propels the 66 mm warhead forward without significant recoil. As the warhead emerges from the launcher, six fins spring out from the base of the rocket tube, stabilizing the warhead's flight.

Once fired the launcher is no longer useful and may be discarded. Due to the single use nature of the weapon, it was issued as a round of ammunition by the Canadian Army and the United States Army.

During the Vietnam and post-Vietnam periods, all issued LAWs were recalled due to instances of the warhead exploding in flight, sometimes injuring the operator. After safety improvements, part of the training and firing drills included the requirement to ensure the words "w/coupler" were included in the text description stenciled on the launcher, which indicated the launcher had the required safety modification(s).

Photos courtesy of the Hall Collection.