GUERRILLA TROOPS (Span. guerra, war ; guerrilla, a little war). Self-constitut ed bodies of armed men in times of war, who form no integral part of the organized army, do not stand on the regular pay-roll of the army, or are not paid at all, take up arms and lay them down at intervals, and carry on petty war, chiefly by raids, extor tion, destruction, and massacre. Lieber, Guerr. Part. 18. See Halleck, Int. Law 386; Wools. Int. Law 299.
Partisan, free-corps, and guerrilla are terms resembling each other considerably in signification ; and, indeed, partisan and guer rilla are frequently used in the same sense. See Halleck, Int. Law 386.
Partisan corps and free-corps both denote bodies detached from the main army ; but the former term refers to the action of the troop, the latter to the composition. The partisan leader commands a corps whose object is to injure the enemy by action sep arate from that of his own main army ; the partisan acts chiefly upon the enemy's lines of connection and communication, and out side of or beyond the lines of operation of his own army, in the rear and on the flanks of the enemy. But he is part and parcel of the army, and, as such, considered entitled to the privileges of the law of war so long as he does not transgress it. Free-corps, on the other hand, are troops not belonging to the regular army, consisting of volunteers generally raised by individuals authorized to do so by the government, used for petty war, and not incorporated with the ordre de ba toyille. The men composing these corps are
entitled to the benefit of the laws of war, un der the same limitations as the partisan corps.
Guerrilla-men, when captured in fair fight and open warfare, should be treated as the regular partisan is, until special crimes, such as murder, or the killing of prisoners, or the sacking of places, are proved against them.
In drawing up the Convention Concerning the Laws and Customs of War on Land, adopted at The Hague in 1899, much diffi culty was experienced in securing an agree ment upon the status to be attributed to militia and corps of volunteers. It was agreed that such guerrilla troops should come under the laws applying to the regular army, provided they be commanded by a per son responsible for his subordinates, wear a distinctive emblem recognizable at a dis tance, carry arms openly, and conduct their operations in accordance with the laws and customs of war. Even the population of an invaded territory, which as a body takes up arms on the approach of the enemy, must be regarded as belligerents, provided they carry arms openly and observe the laws and cus toms of war. II Opp. 70-72.