Methods (and Means) of Warfare
Methods of warfare are the tactics or strategy used in hostilities against an enemy in times of conflict. Means of warfare are the weapons or weapons systems used. The only legitimate objective of war, as defined by the law of armed conflicts, is to weaken and overpower the opponent’s military forces. The history of conflicts illustrates the need to restrict the use of force in order to limit the risks of extermination and total destruction of the enemy.
Within the ambit of interstate conventional warfare, each party to the conflict mirrors the other with regard to potential military resources. Furthermore, the principle of reciprocity in the treatment of combatants facilitates respect for the law of armed conflict. The issue of respect for methods of warfare is more problematic when the powers and means of opposed armed forces are notably unbalanced. This lack of balance may be noted in both international and non-international armed conflicts, in particular where technological means used by the parties vary notably. In non-international armed conflict the lack of balance is further intensified by the fact that the conflict situations oppose national armed forces with armed groups that do not enjoy comparable structure or means. The imbalance between forces and the lack of symmetry between the means often leads the belligerents to avoid direct military confrontation. These methods directly weaken the distinction between civilians and combatants and the choice of military objectives, as well as methods of warfare.
The weakening of the core principle of distinction between civilians and combatants was emphasized by the concepts and methods of the war against terrorism. Hence appear legally ambiguous humanitarian law concepts that mix up elements of humanitarian law with those of law enforcement whose practical application is subject to discretion and arbitrariness. The concept of “double objective” refers to a target with both military and civilian characteristics. The legitimacy of an attack implies the prior assessment of the proportionality between the military advantage and the collateral damages on civilians. The distinction between the status of civilians and that of combatants is disputed in most non-international armed conflicts. This creates debates and uncertainties on the treatment of so-called unlawful combatants and civilians who take part in hostilities. The practice of suicide bombings and targeted killings falls within a form of confrontation that leads in practice to spreading terror among the population of the opponent. Terror is a prohibited method of warfare, yet it continues to be used in order to challenge a given political order or to maintain this order.
The two 1977 Additional Protocols aim to take into account the characteristics of these kinds of conflict. Additional Protocol I limits what may be destroyed in international armed conflicts. It also covers the issue of resistance under situations of occupation. Additional Protocol II confines the confrontations in non-international armed conflicts.
▸ Combatants ▸ Ill treatment ▸ International humanitarian law ▸ Military objectives ▸ Terror ▸ Terrorism
War is a part of history and of international relations. It is a transitional phase and must be conducted in a way that will not make a return to peace impossible. Various international humanitarian law texts therefore establish the principles that limit the choice of methods of warfare.
- The 1899 and 1907 Hague Conventions, as well as the 1949 Geneva Conventions and their 1977 Additional Protocols, set forth the main rules, restrictions, and prohibitions concerning the use of violence and different methods of warfare in international and non-international armed conflicts.
- The conventions define which acts are war crimes and establish sanctioning mechanisms to punish the authors of such crimes. Some of these crimes are defined as grave breaches of the Geneva Conventions or war crimes and therefore come under the principle of universal jurisdiction and the competence of the International Criminal Court.
- Despite the numerous violations of these rules, their repeated use over time has conferred most of them the value of “customary norms.” These rules have been compiled by the ICRC in a study published in 2005 (customary IHL study). The rules are now binding on all parties to a conflict, even States that are not parties to the conventions and organized non-state armed groups that cannot ratify the conventions or have not formally adhered to such rules. They apply almost in the same manner in international and non-international armed conflicts. Rules 1 to 10 of the customary IHL study concern the principle of distinction between civilian and military objectives. Rules 11 to 24 address the principles of precaution and proportionality in attacks. Rules 46 to 65 deal with specific methods of warfare, and Rules 70 to 81 regulate the use of the different types of weapons.
▸ Customary international ▸ law ▸ International Criminal Court ▸ International humanitarian law ▸ Universal jurisdiction ▸ War crimes/Crimes ▸ against humanity (Section 3, “Grave Breaches of International Humanitarian Law”)
Regulating the Weapons of War
The right to choose the methods and means of warfare is not unlimited. International law imposes restrictions on the manufacture and use of certain weapons—namely, those that strike civilians and combatants indiscriminately or cause damage that is extensive or basically irreversible and is disproportionate to any specific military advantage (Rules 7 to 24 of the customary IHL study).
▸ Military objectives ▸ Mines ▸ Weapons
Regulating the Techniques of War
Humanitarian law prohibits gratuitous and wanton violence and destruction. It requires that any means of violence employed (i) be justified by a real and direct military necessity, (ii) be directed to a military objective, and (iii) be proportionate to the threat. Those are known as the principles of distinction, military necessity and proportionality. The application of the principle of proportionality has been extended to the assessment of incidental loss of civilians by the attack of a military objective and the duty to take necessary precautions to limit them.
International humanitarian law prohibits:
- the use of means and methods of warfare of a nature to cause superfluous injury or unnecessary suffering (API Art. 35; Art. 22 of the rules of the 1907 Hague Conventions; and the 1868 Saint Petersburg Declaration);
- carrying out attacks with the goal that there will be no survivors—in other words, giving no quarter (API Arts. 40, 41; Art. 35 of the 1907 Hague Convention on the laws and customs of war). Rule 46 of the customary IHL study provides that “ordering that no quarter will be given, threatening an adversary therewith or conducting hostilities on this basis is prohibited.”
Prohibited methods of warfare include:
- perfidy (API Arts. 37–39; Rules 57–65);
- terror (API Art. 51, APII Art. 13, Rule 2);
- famine (starvation) of civilians (API Art. 54, APII Art. 14, Rule 53);
- reprisals against non-military objectives (GCI Art. 46; GCII Art. 47; GCIII Art. 13; GCIV Art. 33; API Arts. 20, 51–56; Art. 46 of the 1954 Convention on the Protection of Cultural Property);
- attacks against protected persons and civilian objects, indiscriminate attacks (API Arts. 48, 51; Rules 1 and 6);
- attacks aimed at causing damage to the natural environment (API Arts. 35, 52, and 55; Rules 43–45);
- attacks against works and installations containing dangerous forces (API Arts. 52, 56; APII Art. 15; Rule 42);
- pillage of cultural objects and property (GCIV Art. 33; Art. 4 of 1954 Convention on the Protection of Cultural Property; APII Art. 4; Rules 38–41 and 52);
- taking hostages (GCI–IV Art. 3; GCIV Art. 34; API Art. 75; principles of international law established by the statute and judgments of the Nuremberg Tribunals; Art. 12 of the 1979 Convention against the Taking of Hostages; Rule 96);
- using human shields or population movements to favor the conduct of hostilities (GCIV Art. 49; API Art. 51; APII Art. 17; Rules 97 and 129).
▸ Attacks ▸ Famine ▸ Hostages ▸ Human shields ▸ Military necessity ▸ Military objectives ▸ Perfidy ▸ Pillage ▸ Population displacement ▸ Proportionality ▸ Protected objects and property ▸ Protected persons ▸ Reprisals ▸ Terror
Humanitarian law prohibits the use of prisoners of war, the civilian population, and resources in occupied territories for military purposes. It also limits the right of requisition. ▸ Occupied territory ▸ Prisoners of war ▸ Requisition
Military commanders are under the obligation to respect and enforce the respect for international humanitarian law, including the prohibitions listed above. They must:
- take certain precautions when attacking (Rules 15–21 of the customary IHL study);
- ensure that their subordinates know and understand humanitarian law;
- punish any of their subordinates who have acted in violation of these rules.
▸ Attacks ▸ Duty of commanders
The failure to respect these rules may constitute a war crime under international humanitarian law and according to the Statute of the International Criminal Court. ▸ International Criminal Court ▸ War crimes/Crimes against humanity
The Regulation of Methods of Warfare in the Customary IHL Study
Most of the following rules are applicable both in international armed conflicts (IAC) and in non-international armed conflicts (NIAC).
Distinction between Civilian Objects and Military Objectives
Rule 7 . The parties to the conflict must at all times distinguish between civilian objects and military objectives. Attacks may only be directed against military objectives. Attacks must not be directed against civilian objects. [IAC/NIAC]
Rule 11. Indiscriminate attacks are prohibited. [IAC/NIAC]
Rule 12. Indiscriminate attacks are those:
- which are not directed at a specific military objective;
- which employ a method or means of combat which cannot be directed at a specific military objective; or
- which employ a method or means of combat the effects of which cannot be limited as required by international humanitarian law; and consequently, in each such case, are of a nature to strike military objectives and civilians or civilian objects without distinction. [IAC/NIAC]
Proportionality in Attack
Rule 14. Launching an attack which may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated, is prohibited. [IAC/NIAC]
Precautions in Attack
Rule 15. In the conduct of military operations, constant care must be taken to spare the civilian population, civilians and civilian objects. All feasible precautions must be taken to avoid, and in any event to minimise, incidental loss of civilian life, injury to civilians and damage to civilian objects. [IAC/NIAC]
Rule 16 . Each party to the conflict must do everything feasible to verify that targets are military objectives. [IAC/NIAC]
Rule 17. Each party to the conflict must take all feasible precautions in the choice of means and methods of warfare with a view to avoiding, and in any event to minimising, incidental loss of civilian life, injury to civilians and damage to civilian objects. [IAC/NIAC]
Rule 18. Each party to the conflict must do everything feasible to assess whether the attack may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated. [IAC/NIAC]
Rule 19. Each party to the conflict must do everything feasible to cancel or suspend an attack if it becomes apparent that the target is not a military objective or that the attack may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated. [IAC/NIAC]
Denial of Quarter
Rule 46. Ordering that no quarter will be given, threatening an adversary therewith or conducting hostilities on this basis is prohibited. [IAC/NIAC]
Rule 47. Attacking persons who are recognised as hors de combat is prohibited. A person hors de combat is:
- anyone who is in the power of an adverse party;
- anyone who is defenceless because of unconsciousness, shipwreck, wounds or sickness; or
- anyone who clearly expresses an intention to surrender; provided he or she abstains from any hostile act and does not attempt to escape. [IAC/NIAC]
Rule 48. Making persons parachuting from an aircraft in distress the object of attack during their descent is prohibited. [IAC/NIAC]
Destruction and Seizure of Property
Rule 49. The parties to the conflict may seize military equipment belonging to an adverse party as war booty. [IAC]
Rule 50. The destruction or seizure of the property of an adversary is prohibited, unless required by imperative military necessity. [IAC/NIAC]
Rule 51. In occupied territory:
- movable public property that can be used for military operations may be confiscated;
- immovable public property must be administered according to the rule of usufruct; and
- private property must be respected and may not be confiscated except where destruction or seizure of such property is required by imperative military necessity. [IAC]
Rule 52. Pillage is prohibited. [IAC/NIAC]
Starvation and Access to Humanitarian Relief
Rule 53. The use of starvation of the civilian population as a method of warfare is prohibited. [IAC/NIAC]
Rule 54. Attacking, destroying, removing or rendering useless objects indispensable to the survival of the civilian population is prohibited. [IAC/NIAC]
Rule 55. The parties to the conflict must allow and facilitate rapid and unimpeded passage of humanitarian relief for civilians in need, which is impartial in character and conducted without any adverse distinction, subject to their right of control. [IAC/NIAC]
Rule 56. The parties to the conflict must ensure the freedom of movement of authorised humanitarian relief personnel essential to the exercise of their functions. Only in case of imperative military necessity may their movements be temporarily restricted. [IAC/NIAC]
Rule 57. Ruses of war are not prohibited as long as they do not infringe a rule of international humanitarian law. [IAC/NIAC]
Rule 58. The improper use of the white flag of truce is prohibited. [IAC/NIAC]
Rule 59. The improper use of the distinctive emblems of the Geneva Conventions is prohibited. [IAC/NIAC]
Rule 60. The use of the United Nations emblem and uniform is prohibited, except as authorised by the organisation. [IAC/NIAC]
Rule 61. The improper use of other internationally recognised emblems is prohibited. [IAC/NIAC]
Rule 62. Improper use of the flags or military emblems, insignia or uniforms of the adversary is prohibited. [IAC/arguably NIAC]
Rule 63. Use of the flags or military emblems, insignia or uniforms of neutral or other States not party to the conflict is prohibited. [IAC/arguably NIAC]
Rule 64. Concluding an agreement to suspend combat with the intention of attacking by surprise the enemy relying on that agreement is prohibited. [IAC/NIAC]
Rule 65. Killing, injuring or capturing an adversary by resort to perfidy is prohibited. [IAC/NIAC]
▸ Aggression ▸ Annexation ▸ Attacks ▸ Blockade ▸ Bombardment ▸ Cease-fire ▸ Duty of commanders ▸ Evacuation ▸ Extermination ▸ Famine ▸ Geneva Conventions and Protocols ▸ The Hague Conventions ▸ Hostages ▸ Human shields ▸ International Criminal Court ▸ Military necessity ▸ Military objectives ▸ Mines ▸ Population displacement ▸ Proportionality ▸ Reprisals ▸ Requisition ▸ Siege ▸ War ▸ War crimes/Crimes against humanity ▸ Weapons
For Additional Information: Bouchié de Belle, Stéphanie. “Chained to Cannons or Wearing Targets on Their T-shirts: Human Shields in International Humanitarian Law.” International Review of the Red Cross 872 (December 2008): 883–906.
Dinstein, Yoram. The Conduct of Hostilities under the Law of International Armed Conflict . Cambridge: Cambridge University Press, 2004.
Henckaerts, Jean-Marie, and Louise Doswald-Beck, eds. Customary International Law . Vol. 1, The Rules . Cambridge: Cambridge University Press, 2005, esp. parts 3 and 4.
Kretzmer, D. “Targeted Killings of Suspected Terrorists: Extra-Judicial Execution or Legitimate Means of Defence?” European Journal of International Law 16, no. 2 (2005): 171–212.
John-Hopkins, Michael. “Regulating the Conduct of Urban Warfare: Lessons from Contemporary Asymmetric Armed Conflicts.” International Review of the Red Cross 878 (June 2010): 469–93.
“Methods of Warfare.” International Review of the Red Cross 864 (December 2006): 717–963.
Mulinen, Frederic de. Handbook on the Law of War for Armed Forces . Geneva: ICRC, 1989.
Munir, Muhammad. “Suicide Attacks and Islamic Law.” International Review of the Red Cross 869 (March 2008): 71–89.
Quéguiner, Jean François. “Precautions under the Law Governing the Conduct of Hostilities.” International Review of the Red Cross 864 (December 2006): 793–821.
Vautravers, Alexandre. “Military Operations in Urban Areas.” International Review of the Red Cross 878 (June 2010): 437–52.