For this first debate, the Review asked two members of its Editorial Board, Professor Marco Sassòli and Professor Yuval Shany, to debate on the topic of equality of states and armed groups under international humanitarian law. Professor René Provost comments on this debate, adding a third dimension to the discussion. The crucial question is whether it is realistic to apply the current legal regime to non-state armed groups. How can armed groups, with sometimes very limited means and low levels of organization, meet the same obligations as states? What are the incentives for armed groups to respect rules that their opponents have enacted? Why should they respect any rules when the very fact of taking arms against the state already makes them 'outlaws'? All participants in this discussion share an aspiration to ensure better legal protection for all those affected by armed conflicts. Professors Sassòli and Shany have agreed to present two 'radically' opposed stances, Professor Sassòli maintaining that equality should be reconsidered and replaced by a sliding scale of obligations, and Professor Shany rebutting this assertion. Professor Provost then reflects on the stances put forward by the two debaters and invites us to revisit the very notion of equality of belligerents. The debaters have simplified their complex legal reasoning for the sake of clarity and brevity. Readers of the Review should bear in mind that the debaters actual legal positions are more nuanced than they may appear in this debate. Related article: The move to substantive equality in international humanitarian law: a rejoinder to Marco Sassòli and Yuval Shany, by Professor René Provost