International humanitarian law (IHL): a constantly evolving body of law

The Geneva Convention of 1864, concluded to improve the fate of soldiers wounded fighting for their armies in the field, was the first convention adopted at the initiative of the International Committee of the Red Cross (ICRC) to protect one category of victims of conflicts. By 2009 the ICRC had counted a hundred or so documents no less, including conventions and declarations published over the years on the law governing armed conflicts.

Protecting victims

The conventions stemming from the ‘Law of Geneva’ have been fairly regularly developed. The 1864 Convention was reviewed in 1906, then again in 1929, when it was joined by a Convention relative to the treatment of prisoners of war. This convention developed the minimum provisions set out in the Hague Conventions of 1899 and 1907. After World War II, civilians were very poorly protected by customary law in this respect. The Fourth Geneva Convention, adopted in 1949, actually officially covers this category of victims. The other conventions of 1949 build on previous provisions in favour of the wounded and sick in military campaigns on land and at sea and also prisoners of war. This constituted a first breakthrough in favour of the victims of non-international armed conflicts under the respective Conventions’ common Article 3.

The conduct of hostilities (methods and means of combat)

The conduct of hostilities, previously governed almost exclusively by customary law, was partially codified at the First and Second Peace Conferences held at The Hague in 1899 and 1907. That codification was famously accompanied by the so-called ‘Martens Clause’, named after the Russian plenipotentiary who proposed it, which read as follows:

“Until a more complete code of the laws of war is issued, the High Contracting Parties think it right to declare that in cases not included in the Regulations adopted by them, populations and belligerents remain under the protection and empire of the principles of international law, as they result from the usages established between civilised nations, from the laws of humanity and the requirements of the public conscience”.

The Law of The Hague would not undergo any more real conventional development until 1977, with the exception of the 1925 Protocol for the Prohibition of the Use of Asphyxiating, Poisonous or Other Gases, and of Bacteriological Methods of Warfare, the 1954 Hague Convention for the Protection of Cultural Property in the Event of Armed Conflict, and the 1976 Convention on the Prohibition of Military or any Hostile Use of Environmental Modification Techniques.

1977: A turning point in two respects

1977 brought the Additional Protocols I and II to the 1949 Geneva Conventions. Not only did these Protocols reaffirm and develop certain provisions of the Conventions; Protocol I and (to a somewhat lesser extent) Protocol II on non-international armed conflicts also took up, specified and expanded the rules and principles set out in the Law of the Hague on the conduct of hostilities. This was a first turning point: the Law of Geneva and the Law of The Hague were joined up, with a cautious reiteration of an updated Martens Clause.

The second turning point came when the diplomatic conference that adopted the Protocols also worked intensively on a more informal basis to limit the use of conventional arms from a humanitarian point of view, and sponsored two conferences of experts on this topic. The conference called on the States to proceed with the swift formalisation of the work it had done in this connection and, in so doing, reinitiated the development of law in this domain, not merely from the viewpoint of advocating disarmament, but also from the angle of humanitarian law.

Conventional weapons that “may cause unnecessary suffering or have indiscriminate effects” after 1977

Consequently, it was expressly from this point on that negotiations began on the Convention on Prohibitions or Restrictions on the Use of Certain Conventional Weapons Which May be Deemed to be Excessively Injurious or to Have Indiscriminate Effects, adopted in Geneva on 10 October 1980.
The latest developments regarding this Convention, as well as the 1997 Conventions of 1997 banning anti-personnel mines and the 2008 Convention on Cluster Munitions stemmed from the same philosophy.

The doctrinal interpretation and codification of IHL since 1977

Undeniably, substantial progress has been made in humanitarian law since the adoption of the 1977 Additional Protocols to the Geneva Conventions of 1949. Nonetheless, some issues are clearly still covered by a customary law that is sometimes uncertain or subject to interpretation. The unexpected emergence of new or poorly known actors may be a cause of hesitation regarding applicable law. As a result there has been a vast number of colloquiums, articles of doctrine and meetings of experts on the issues in question, and we therefore draw your attention to a few of the resulting documents:

  • The San Remo Manual on International Law Applicable to Armed Conflictat Sea was drawn up between 1988 and 1994 by a group of experts in international law and naval experts under the aegis of the San Remo International Institute of International Law. Some of the provisions contained in the manual may seem like developments of the law, but most of them are deemed to expound law that is already in force.
  • The ICRC’s 2005 study on customary international humanitarian law contains a list of 161 rules of customary IHL, based on the States’ legal practices. Not all specialists agree on the conclusions of the study, but it has become the standard reference work on the subject, and the study may well prompt considerable advances in the law governing non-international armed conflicts.  • 
  • The 2008 Montreux Document on Pertinent International Legal Obligations and Good Practices for States related to the Operations of Private Military and Security Companies during Armed Conflict was the fruit of a joint initiative launched in 2006 by Switzerland and the ICRC.
  • IHL is based on the principle of drawing a distinction between combatants and civilians who are presumed not to be directly involved in the hostilities and, as a result, need to be protected against attacks. After six years of discussion and research conducted by experts, in 2009 the ICRC published its Interpretive Guidance on the Notion of Direct Participation in Hostilities under IHL with a view to clarifying the meaning and consequences of this notion.

This doctrinal shift is still going on, hence for example the Program on Humanitarian Policy and Conflict Research at Harvard University, which since 2004 has piloted a codification of international law governing aerial warfare and the use of missiles in the conduct of hostilities.

Curbing violations of the rules set out in the law of armed conflict

For a long time, this aspect of the law of armed conflict remained the sole responsibility of national case law. The tribunals set up in Nuremberg and Tokyo immediately after World War II remained notable exceptions until the UN Security Council’s establishment of the International Criminal Tribunal for the Former Yugoslavia (ICTY) in 1993. The Security Council then went on to set up the International Criminal Tribunal for Rwanda in 19914 and the International Criminal Tribunal for Sierra Leone in 2002. In addition, between 2001 and 2007, Cambodia had Extraordinary Chambers in the Courts of Cambodia, following a cooperation agreement concluded with the United Nations in 2004. That agreement allowed above all for the participation of international legal experts in those Chambers with a view to pursuing the perpetrators of the genocide in 1975. In the meantime, in 1998 an international conference adopted the Rome Statute of the International Criminal Court. Consequently, since 1993 there has been a major advance in IHL in the domain that had previously been its sparsest area, namely punishing those who fail to respect international humanitarian law. It is worth pointing out that the progress made also involves the repression of crimes against humanity and genocide, which is a broader domain not merely confined to armed conflicts.

Belgium and the development of IHL

Belgium has always played an active role in the development of IHL and supported efforts made in this connection, first and foremost by the ICRC. As long ago as the 19th century, our country supported the creation of the first National Society of the Red Cross, recognising it as auxiliary to Belgium’s public authorities. In this way, Belgium helped to lay the foundations of the first Geneva Convention in 1864. In 1874 it hosted the conference that led to the Brussels Declaration of 1874, the precursor of the 1899 and 1907 Hague Conventions on the Laws and Customs of War on Land. Today, Belgium’s involvement is just as extensive and widely recognised, its actions in the domains of anti-personnel mines and cluster munitions being good examples, along with its efforts to shore up the International Criminal Court and bolster the ICC’s powers.  

Specific links:

IHL- related texts and conventions on the ICRC website

Links on this website:

External links: