Study on Customary International Humanitarian Law: A Contribution to the Understanding and Respect for the Rule of Law in Armed Conflict

• Author: Jean-Marie Henckaerts
• Position: Legal Adviser, Legal Division, International Committee of the Red Cross (ICRC)
• Pages: 37-79

II

Study on Customary International

Humanitarian Law:

AContribution to the Understanding and

Respect for the Rule of Law in Armed Conflict

Jean-Marie Henckaerts*

Abstract

This article explains the rationale behind astudy on customary international

humanitarian law recently undertaken by the International Committee of

the Red Cross (ICRC) at the request of the International Conference of the Red

Cross and Red Crescent. It describes the methodology used and how the study was

organized and summarizes some major findings. It does not, however, purport to

provide acomplete overview or analysis of these findings.

Introduction

In the 50 years or so since the adoption of the Geneva Conventions of 1949, man-

kind has experienced an alarming number of armed conflicts affecting almost every

continent. During this time, the four Geneva Conventions and their Additional

*Legal Adviser, Legal Division, International Committee of the Red Cross (ICRC). The views in

this article are those of the author and do not necessarily reflect those of the ICRC. This article

was first published in the International Review ofthe Red Cross, Volume 87, Number 857, March

2005, at page 175 and is reprinted with permission. ©2006 by Jean-Marie Henckaerts.

Customary International Humanitarian Law Study

Protocols of 1977 have provided legal protection to persons not or no longer par-

ticipating directly in hostilities (the wounded, sick and shipwrecked, persons de-

prived of their liberty for reasons related to an armed conflict, and civilians). Even

so, there have been numerous violations ofthese treaties, resulting in suffering and

death which might have been avoided had international humanitarian law been

better respected.

The general opinion is that violations of international humanitarian law are not

due to the inadequacy of its rules. Rather, they stem from an unwillingness to re-

spect the rules, from insufficient means to enforce them, from uncertainty as to

their application in some circumstances and from alack of awareness of them on

the part of political leaders, commanders, combatants and the general public.

The International Conference for the Protection of War Victims, convened in

Geneva in August-September 1993, discussed in particular ways to address viola-

tions of international humanitarian law but did not propose the adoption of new

treaty provisions. Instead, in its Final Declaration adopted by consensus, the Con-

ference reaffirmed "the necessity to make the implementation ofhumanitarian law

more effective" and called upon the Swiss government "to convene an open-ended

intergovernmental group of experts to study practical means of promoting full re-

spect for and compliance with that law, and to prepare areport for submission to

the States and to the next session of the International Conference of the Red Cross

and Red Crescent." 1

The Intergovernmental Group ofExperts for the Protection ofWar Victims met

in Geneva in January 1995 and adopted aseries of recommendations aimed at en-

hancing respect for international humanitarian law, in particular by means of pre-

ventive measures that would ensure better knowledge and more effective

implementation of the law. Recommendation II of the Intergovernmental Group

of Experts proposed that:

The ICRC be invited to prepare, with the assistance of experts in IHL [international

humanitarian law] representing various geographical regions and different legal

systems, and in consultation with experts from governments and international

organizations, areport on customary rules of IHL applicable in international and non-

international armed conflicts, and to circulate the report to States and competent

international bodies.2

In December 1995, the 26th International Conference of the Red Cross and

Red Crescent endorsed this recommendation and officially mandated the ICRC

to prepare areport on customary rules of international humanitarian law appli-

cable in international and non-international armed conflicts.3Nearly ten years

later, in 2005, after extensive research and widespread consultation of experts,

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Jean-Marie Henckaerts

this report, now referred to as the study on customary international humanitar-

ian law, has been published.4

Purpose

The purpose of the study on customary international humanitarian law was to

overcome some of the problems related to the application of international hu-

manitarian treaty law. Treaty law is well developed and covers many aspects of

warfare, affording protection to arange of persons during wartime and limiting

permissible means and methods of warfare. The Geneva Conventions and their

Additional Protocols provide an extensive regime for the protection of persons

not or no longer participating directly in hostilities. The regulation of means and

methods of warfare in treaty law goes back to the 1868 St. Petersburg Declaration,

the 1899 and 1907 Hague Regulations and the 1925 Geneva Gas Protocol, and has

most recently been addressed in the 1972 Biological Weapons Convention, the

1977 Additional Protocols, the 1980 Convention on Certain Conventional

Weapons and its five Protocols, the 1993 Chemical Weapons Convention and the

1997 Ottawa Convention on the Prohibition of Anti-personnel Mines. The pro-

tection of cultural properly in the event of armed conflict is regulated in detail in

the 1954 Hague Convention and its two Protocols. The 1998 Statute of the Inter-

national Criminal Court contains, inter aliayalist of war crimes subject to the ju-

risdiction of the Court.

There are, however, two serious impediments to the application of these treaties

in current armed conflicts and which explain why astudy on customary interna-

tional humanitarian law is necessary and useful. First, treaties apply only to the

States that have ratified them. This means that different treaties of international

humanitarian law apply in different armed conflicts depending on which treaties

the States involved have ratified. While the four Geneva Conventions of 1949 have

been universally ratified, the same is not true for other treaties of humanitarian

law, for example the Additional Protocols. Even though Additional Protocol Ihas

been ratified by more than 160 States, its efficacy today is limited because several

States that have been involved in international armed conflicts are not party to it.

Similarly, while nearly 160 States have ratified Additional Protocol II, several States

in which non-international armed conflicts are taking place have not done so. In

these non-international armed conflicts, common Article 3 of the four Geneva

Conventions often remains the only applicable humanitarian treaty provision. The

first purpose of the study was therefore to determine which rules of international

humanitarian law are part of customary international law and therefore applicable

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