One of the key elements of international humanitarian law is the clear distinction between members of the armed forces and civilians. In contemporary armed conflicts, however, the proximity of civilians to military operations and their increased assumption of traditionally military functions lead to confusion as to the implementation of the principle of distinction.
Throughout history, civilians have always contributed to the war effort to a greater or lesser degree, whether through their involvement in arms production, or by providing economic, political and administrative support. Typically, however, they were not present at the battlefront and only a small number of civilians was actually involved in the conduct of military operations.
In these circumstances, it was comparatively easy to determine who was a combatant, and therefore a legitimate target, and who was a civilian protected under IHL from direct attack.
In the past few decades, battlefields have become less distinct with fighting taking place in civilian population centres. Civilians have been increasingly involved in activities more closely related to the conduct of hostilities, thus blurring the distinction between civilian and military functions. This has created uncertainty as to how the principle of distinction, the very cornerstone of IHL, should be implemented in the reality of contemporary military operations.
A further problem arises if armed actors do not distinguish themselves from civilians during clandestine operations, for example, or when they act as "farmers by day and fighters at night". As a consequence, the armed forces become unable to properly identify their adversary, and peaceful civilians are more likely to fall victim of erroneous or arbitrary targeting.
According to IHL, civilians must be protected against direct attack, "unless and for such time as they take a direct part in hostilities". However, neither the Geneva Conventions nor their Additional Protocols provide a definition of what conduct amounts to direct participation in hostilities. The contemporary challenge, therefore, is to provide clear criteria for the distinction not just between civilians and the armed forces, but also between peaceful civilians and civilians who directly participate in hostilities.
The ICRC believes three key questions need clarification: (1) Who is considered a civilian for the purposes of conducting hostilities? (2) What conduct amounts to direct participation in hostilities? (3) What are the precise modalities according to which civilians directly participating in hostilities lose their protection against direct attack?
In 2003 the ICRC, in cooperation with the TMC Asser Institute, started a process of research and consultation on the interpretation of IHL as far as it relates to direct participation in hostilities.
Five informal expert meetings were held in The Hague and Geneva between 2003 and 2008, bringing together up to 50 legal experts from military, governmental and academic circles, as well as from international organizations and NGOs. The ICRC was asked to take the lead in the process.
In 2009, after six years of discussions and research, the ICRC published the document entitled "Interpretive Guidance on the Notion of Direct Participation in Hostilities under IHL" as well as all documents produced during the proceedings of the expert process.