The Commander's Handbook on the Law of Naval Operations
Office of the Judge Advocate General, United States Navy
Chapter 5 - Principles and Sources of the Law of Armed Conflict
[Relevant sections only. Particularly relevant sections highlighted in red.]
5.1 WAR AND THE LAW
Article 2 of the United Nations Charter requires all nations to settle their international disputes by peaceful means and to refrain from the threat or use of force against the territorial integrity or political independence of other nations. The United Nations Charter prohibits the use of force by member nations except as an enforcement action taken by or on behalf of the United Nations (as in the Gulf War) or as a measure of individual or collective self-defense. It is important to distinguish between resort to armed conflict, and the law governing the conduct of armed conflict. Regardless of whether the use of armed force in a particular circumstance is prohibited by the United Nations Charter (and therefore unlawful), the manner in which the resulting armed conflict is conducted continues to be regulated by the law of armed conflict. (For purposes of this publication, the term "law of armed conflict" is synonymous with "law of war.")
5.2 GENERAL PRINCIPLES OF THE LAW OF ARMED CONFLICT
The law of armed conflict seeks to prevent unnecessary suffering and destruction by controlling and mitigating the harmful effects of hostilities through minimum standards of protection to be accorded to "combatants" and to "noncombatants" and their property. (See paragraphs 5.3 and 11.1.) To that end, the law of armed conflict provides that:
1. Only that degree and kind of force, not otherwise prohibited by the law of armed conflict, required for the partial or complete submission of the enemy with a minimum expenditure of time, life, and physical resources may be applied.
2. The employment of any kind or degree of force not required for the purpose of the partial or complete submission of the enemy with a minimum expenditure of time, life, and physical resources, is prohibited.
3. Dishonorable (treacherous) means, dishonorable expedients, and dishonorable conduct during armed conflict are forbidden.
The law of armed conflict is not intended to impede the waging of hostilities. Its purpose is to ensure that the violence of hostilities is directed toward the enemy's forces and is not used to cause purposeless, unnecessary human misery and physical destruction. In that sense, the law of armed conflict complements and supports the principles of warfare embodied in the military concepts of objective, mass, economy of force, surprise, and security. Together, the law of armed conflict and the principles of warfare underscore the importance of concentrating forces against critical military targets while avoiding the expenditure of personnel and resources against persons, places, and things that are militarily unimportant. However, these principles do not prohibit the application of overwhelming force against enemy combatants, units and material.
5.3 COMBATANTS AND NONCOMBATANTS
The law of armed conflict is based largely on the distinction to be made between combatants and noncombatants. In accordance with this distinction, the population of a nation engaged in armed conflict is divided into two general classes: armed forces (combatants) and the civilian populace (noncombatants). Each class has specific rights and obligations in time of armed conflict, and no single individual can be simultaneously a combatant and a noncombatant.
The term "combatant" embraces those persons who have the right under international law to participate directly in armed conflict during hostilities. Combatants, therefore, include all members of the regularly organized armed forces of a party to the conflict (except medical personnel, chaplains, civil defense personnel, and members of the armed forces who have acquired civil defense status), as well as irregular forces who are under responsible command and subject to internal military discipline, carry their arms openly, and otherwise distinguish themselves clearly from the civilian population.
Conversely, the term "noncombatant" is primarily applied to those individuals who do not form a part of the armed forces and who otherwise refrain from the commission or direct support of hostile acts. In this context, noncombatants and, generally, the civilian population, are synonymous. The term noncombatants may, however, also embrace certain categories of persons who, although members of or accompanying the armed forces, enjoy special protected status, such as medical officers, corpsmen, chaplains, technical (i.e., contractor) representatives, and civilian war correspondents. (See Chapter 11.) The term is also applied to armed forces personnel who are unable to engage in combat because of wounds, sickness, shipwreck, or capture.
Under the law of armed conflict, noncombatants must be safeguarded against injury not incidental to military operations directed against combatant forces and other military objectives. In particular, it is forbidden to make noncombatants the object of attack.
Because only combatants may lawfully participate directly in armed combat, noncombatants that do so are acting unlawfully and are considered illegal combatants. See paragraphs 11.5 (Medical Personnel and Chaplains) and 12.7.1 (Illegal Combatants).
5.4 SOURCES OF THE LAW OF ARMED CONFLICT
As is the case with international law generally, the principal sources of the law of armed conflict are custom, as reflected in the practice of nations, and international agreements.
5.4.1 Customary Law. The customary international law of armed conflict derives from the practice of military and naval forces in the field, at sea, and in the air during hostilities. When such a practice attains a degree of regularity and is accompanied by the general conviction among nations that behavior in conformity with that practice is obligatory, it can be said to have become a rule of customary law binding upon all nations. It is frequently difficult to determine the precise point in time at which a usage or practice of warfare evolves into a customary rule of law. In a period marked by rapid developments in technology, coupled with the broadening of the spectrum of conflict to encompass insurgencies and state-sponsored terrorism, it is not surprising that nations often disagree as to the precise content of an accepted practice of armed conflict and to its status as a rule of law. This lack of precision in the definition and interpretation of rules of customary law has been a principal motivation behind efforts to codify the law of armed conflict through written agreements (treaties and conventions.) However, the inherent flexibility of law built on custom and the fact that it reflects the actual--albeit constantly evolving--practice of nations, underscore the continuing importance of customary international law in the development of the law of armed conflict.
5.4.2 International Agreements. International agreements, whether denominated as treaties, conventions, or protocols, have played a major role in the development of the law of armed conflict. Whether codifying existing rules of customary law or creating new rules to govern future practice, international agreements are a source of the law of armed conflict. Rules of law established through international agreements are ordinarily binding only upon those nations that have ratified or adhered to them. Moreover, rules established through the treaty process are binding only to the extent required by the terms of the treaty itself as limited by the reservations, if any, that have accompanied its ratification or adherence by individual nations. Conversely, to the extent that such rules codify existing customary law or otherwise come, over time, to represent a general consensus among nations of their obligatory nature, they are binding upon party and non-party nations alike.
Principal among the international agreements reflecting the development and codification of the law of armed conflict are the Hague Regulations of 1907, the Gas Protocol of 1925, the Geneva Conventions of 1949 for the Protection of War Victims, the 1954 Hague Cultural Property Convention, the Biological Weapons Convention of 1972, and the Conventional Weapons Convention of 1980. Whereas the 1949 Geneva Conventions and the 1977 Protocols Additional thereto address, for the most part, the protection of victims of war, the Hague Regulations, the Geneva Gas Protocol, 1993 Chemical Weapons Convention, Hague Cultural Property Convention, Biological Weapons Convention, and the Conventional Weapons Convention are concerned, primarily, with controlling the means and methods of warfare. The most significant of these agreements (for purposes of this publication) are listed chronologically as follows:
1. 1907 Hague Convention Respecting the Laws and Customs of War on Land (Hague IV)
2. 1907 Hague Convention Respecting the Rights and Duties of Neutral Powers and Persons in Case of War on Land (Hague V)
3. 1907 Hague Convention Relative to the Laying of Automatic Submarine Contact Mines (Hague VIII)
4. 1907 Hague Convention Concerning Bombardment by Naval Forces in Time of War (Hague IX)
5. 1907 Hague Convention Relative to Certain Restrictions with Regard to the Exercise of the Right of Capture in Naval War (Hague XI)
6. 1907 Hague Convention Concerning the Rights and Duties of Neutral Powers in Naval War (Hague XIII)
7. 1925 Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous, or Other Gases, and of Bacteriological Methods of Warfare
8. 1936 London Protocol in Regard to the Operations of Submarines or Other War Vessels with Respect to Merchant Vessels (Part IV of the 1930 London Naval Treaty)
9. 1949 Geneva Convention (I) for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field*
10. 1949 Geneva Convention (II) for the Amelioration of the Condition of Wounded, Sick, and Shipwrecked Members of Armed Forces at Sea*
11. 1949 Geneva Convention (III) relative to the Treatment of Prisoners of War*
12. 1949 Geneva Convention (IV) relative to the Protection of Civilian Persons in Time of War*
13. 1954 Hague Convention for the Protection of Cultural Property in the event of armed conflict
[Items 14 through 18 have been omitted because they were not in force in 1967.]
An asterisk (*) indicates that signature or ratification of the United States was subject to one or more reservations or understandings. The United States is a party to, and bound by, all of the foregoing conventions and protocols, except numbers 13, 15, 16 and 18. The United States has decided not to ratify number 15 (Additional Protocol I). The United States has ratified number 17, Protocols I and II, but has not ratified Protocol III.
5.5 RULES OF ENGAGEMENT
During wartime or other periods of armed conflict, U.S. rules of engagement reaffirm the right and responsibility of the operational commander generally to seek out, engage, and destroy enemy forces consistent with national objectives, strategy, and the law of armed conflict.