the action of a member of the guerrilla force after identifying a legal target, as with the command-detonated mode of the M18A1 Claymore Antipersonnel Mine, the device is not considered a mine within the context of the Ottawa Treaty. Such devices often are used to initiate combat in an ambush, combining surprise with an intense burst of fragments. U.S. policy states that a directional mine of this type may be emplaced if: They are not left out longer than 72 hours. The Claymores are located in the immediate proximity of the military unit that emplaced them. The area is monitored by military personnel to ensure civilians stay out of the area. A common use of mines in guerrilla warfare, however, would be to emplace them behind a retreating guerrilla force, so the pursuit force would trigger them. Modern mines disarm themselves after a period of time, but the majority of both purpose-built and improvised mines do not and present the chief humanitarian concern. U.S. policy commits to stop using manufactured mines, which do not automatically disarm, by 2010 "with exception for use for mine action/demining training and research purposes. The US no longer uses non-detectable land mines of any type", although these restrictions all apply to mines manufactured by the United States. The use of improvised mines and boobytraps, however, is a continuing issue. Since a guerrilla force expects to have the population become increasingly loyal to it, there is an obvious psychological problem with leaving an area with active explosive devices. Especially when a guerrilla force has limited supplies, there is tactical utility to improvising devices, which could be as simple as a hand grenade, fastened next to a trail, and with a taut wire attached to the activating lever of the grenade. Stepping on the wire would pull out the safety ring and start the detonation sequence of the grenade. SF policy does not clearly address this type of device, or those made completely from local materials and having no automatic disarming features. The U.S. Rules of Engagement might ban such devices, but, especially in urban or jungle areas where the guerrillas are not constantly observed, the ban might not be enforced. Sniping Snipers, when the term is used properly, are highly skilled riflemen that use specialized weapons and tactics to attack specific personnel and equipment far outside normal rifle range. SF sniper training is separate from the