1 The Security Council and the Responsibility to Protect in the Age of New Wars.- 2 Legal Theory and Methodology.- 3 The Security Council and International Law.- 4 The International Law of Atrocity Crime Prevention.- 5 Multilateral Debates on R2P and the Protection of Civilians, and Their Impact on General and Treaty Law.- 6 Security Council Practice on Atrocity Crime Prevention Since the End of the Cold War.- 7 Conclusions.