In the more than thirty years that have passed since the adoption of the Additional Protocols to the Geneva Conventions of 1949, the Geneva Conventions have not been revisited to evaluate whether they still effectively regulate their subject matter. Indeed, even if the Geneva Conventions were debated for revision, it seems highly unlikely that such revision would actually go forward. There are so many parties with a stake in the conduct of armed conflict that it is doubtful that any kind of consensus could be reached. A graphic example of the difficulties of achieving consensus could be seen when the Expert Process convened to discuss the concept of Direct Participation in Hostilities. Disagreements over the final text, known as the Interpretive Guidance on Direct Participation in Hostilities, resulted in almost one-third of the fifty experts involved withdrawing their names from the document.

This paper will review the history of international humanitarian law and regulation of irregular participation in armed conflict as a case study to demonstrate the increasingly difficult task of achieving international consensus on the rule of law during armed conflict. From the first provisions in the Hague Regulations regarding levée en masse, to the Geneva Conventions and the Additional Protocols, this paper will look at how nonconventional combatancy has been regulated, and examine the debates surrounding the expansion of the legal category of “combatant.” This paper will culminate in an analysis of the International Committee of the Red Cross (ICRC) Expert Process on Direct Participation in Hostilities, finding both the final Interpretive Guidance, and the controversy leading up to and surrounding its publication, are demonstrative of the obvious stumbling blocks facing any new treaties regarding participation in armed conflict.