This chapter charts the debate between those who believe that the protection of civilians from genocide and mass atrocities ought to trump the principle of non-intervention in certain circumstances and those who oppose this proposition. This has become a particular problem in the post-Cold War world where atrocities in places like Rwanda, Bosnia, and Darfur prompted calls, in the West especially, for international society to step in to protect the victims with military force if necessary. While intervening to protect populations from mass atrocities does have moral appeal, humanitarian intervention causes problems for international security by potentially compromising the rules governing the use of force in world politics. Since the end of the Cold War, a broad international consensus has emerged around a principle called the ‘Responsibility to Protect’ (R2P). The R2P holds that states have a responsibility to protect their populations from genocide and mass atrocities and that the international community has a duty to help states fulfil their responsibilities and use various measures to protect populations when their own states are manifestly failing to do so. In 2011, the principle helped the UN Security Council authorize the use of force against a sovereign state for human protection purposes for the first time in its history.
