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ICRC Study on Customary Rules of International Humanitarian Law

05-03-2005 by Jean-Marie Henckaerts

The ICRC has prepared a report on customary rules of international humanitarian law applicable in international and non-international armed conflicts. The result is a set of two volumes entitled "Customary International Humanitarian Law" published by Cambridge University Press in March 2005.

See below the table of contents of the ICRC study.

In December 1995 the 26th International Conference of the Red Cross and Red Crescent invited the ICRC to prepare a report on customary rules of international humanitarian law applicable in international and non-international armed conflicts. The ICRC accepted this invitation, a Steering Committee to guide the study was set up in 1996 and research started in earnest in 1997.

 Why this study? Treaty law and customary international law are the main sources of international law. In the area of international humanitarian law, treaty law is well developed in general. However, there are few treaty rules regulating non-international conflicts. In fact, in situations not covered by Additional Protocol II, there is only one article covering non-international conflicts, namely common article 3. While common article 3 is extremely useful, it is far from complete. For example, it is virtually silent on questions related to the conduct of hostilities. Additional treaty law could not easily fill this gap because it would be extremely difficult and time-consuming to have states adopt a new treaty on non-international conflicts which would still need states'ratification to enter into force. Therefore the idea arose to look into the other source of international law, namely customary international law which has the additional advantage that it binds all states as such.

 What is customary international law? Unlike treaty law, customary international law is not written. To prove that a certain rule is customary one has to show that it is reflected in state practice and that there exists a conviction in the international community that such practice is required as a matter of law. In this context, " practice " relates to official state practice and therefore includes formal statements by states. A contrary practice by some states does not prevent the existence of a rule of customary international law as long as this practice is generally considered as a violation of the existing rule and not as indications of the recognition of a new rule. State practice in this context does not mean age-old practice. In general, we have focused on state practice during the last twenty years. Customary international law can emerge in an even shorter period of time.

 How has the study been organized? The study encompasses research into state practice as reflected in international sources as well as in national sources. The actual research was done by 6 international research teams, fifty national research teams and two ICRC researchers who gathered state practice on the basis of the ICRC archives related to some thirty recent armed conflicts. The enormous amount of material collected has been catalogued in 6 chapters: (1) principle of distinction, (2) methods of warfare, (3) weapons, (4) specific protections, (5) treatment of persons, (6) accountability and implementation. The result of this work is 6 consolidated practice reports which contain a summary of all state practice gathered and 6 executive summaries which contain the preliminary assessment of the Steering Committee as to what appears to be customary with a brief explanation as to why. In 1999 two meetings of some 50 experts have been held to discuss this preliminary assessment.

 What is next? On the basis of these materials and discussions the ICRC is now writing its report on customary IHL. This report will contain a list of rules found to be customary with a commentary and also indications of trends in practice where no clear custom has emerged. In addition, the consolidated practice reports are being edited and updated to be published together with the main report. The result will be a set of two volumes entitled " Customary International Humanitarian Law " : Volume 1 " Rules " and Volume 2 " Practice " to be published by Cambridge University Press in 2004. It is foreseen that Volume 1 will be translated in French, Spanish, Arabic, Russian and Chinese.

 How can the study be used? The study will be useful in many ways and the ICRC is open to suggestions in this respect. Here a few examples:

1. Rules of customary international law apply to all states. As a result, the rules that have been identified as customary international law can be invoked against every state. This will be particularly useful where states have not ratified the Additional Protocols, the Convention on Certain Conventional Weapons (CCW) and its protocols, and the Hague Convention on the Protection of Cultural Property in the Event of Armed Conflict and its protocols.

2. Treaty law regulating non-international armed conflicts is much less developed in comparison with international armed conflicts, especially concerning the conduct of hostilities. Rules of customary international law can usefully remedy this lack of development to the extent that State practice has led to the creation of rules of customary international law applicable to non-international armed conflicts and to the conduct of hostilities in such conflicts.

3. The study can be used to convinc e governments to ratify certain treaties. If it is shown that certain rules are already customary international law, states should be less hesitant to ratify treaties which contain the same rules.

4. The study can serve as a dissemination tool. Customary international law takes into account the practices and beliefs of all states around the world. It is culturally neutral so to speak.

5. The study can also serve the military. Military manuals should not fall below the standards set by customary international law. Military training should at least be based on these same standards.

6. International (criminal) tribunals which have to apply customary international law could use the study. National courts could use the study as well because customary international law is a source of law in many domestic legal systems. Lawyers appearing before these courts could also rely on the study.

7. The study will also serve to indicate areas of international humanitarian in which there is no agreement and areas where the situation is unclear.


Table of contents of the ICRC Study on "Customary Rules of International Humanitarian Law" 
A set of two volumes to be published by Cambri dge University Press in 2004.

 Part I. The Principle of Distinction  

Chapter 1. Distinction between Civilians and Combatants

Chapter 2. Distinction between Civilian Objects and Military Objectives

Chapter 3. Indiscriminate Attacks

Chapter 4. Proportionality in Attack

Chapter 5. Precautions in Attack

Chapter 6. Precautions against the Effects of Attacks

 Part II. Specifically Protected Persons and Objects  

Chapter 7. Medical and Religious Personnel and Objects

Chapter 8. Humanitarian Relief Personnel and Objects

Chapter 9. Personnel and Objects Involved in a Peacekeeping Mission

Chapter 10. Journalists

Chapter 11. Protected Zones

Chapter 12. Cultural Property

Chapter 13. Works and Installations Containing Dangerous Forces

Chapter 14. The Natural Environment

 Part III. Specific Methods of Warfare  

Chapter 15. Denial of Quarter

Chapter 16. Destruction and Seizure of Property

Chapter 17. Starvation and Access to Humanitarian Relief

Chapter 18. Deception

Chapter 19. Communication with the Enemy

 Part IV. Weapons  

Chapter 20. General Principles

Chapter 21. Poison

Chapter 22. Nuclear Weapons

Chapter 23. Biological Weapons

Chapter 24. Chemical Weapons

Chapter 25. Expanding Bullets

Chapter 26. Exploding Bullets

Chapter 27. Weapons Primarily Injuring by Non-detectable Fragments

Chapter 28. Booby-traps

Chapter 29. Landmines

Chapter 30. Incendiary Weapons

Chapter 31. Blinding Laser Weapons

 Part V. Treatment of Civilians and Persons Hors de Combat  

Chapter 32. Fundamental Guarantees

Chapter 33. Combatants and Prisoner-of-War Status

Chapter 34. The Wounded, Sick and Shipwrecked

Chapter 35. The Dead

Chapter 36. The Missing

Chapter 37. Persons Deprived of Their Liberty

Chapter 38. Displacement and Displaced Persons

Chapter 39. Other Persons with Specific Needs

 Part VI. Implementation  

Chapter 40. Compliance with International Humanitarian Law

Chapter 41. Enforcement of International Humanitarian Law

Chapter 42. Reparation

Chapter 43. Individual Responsibility

Chapter 44. War Crimes