After at least 800.000 Tutsi and moderate Hutu had been killed in the Rwandan genocide, while the United Nations Security Council (UNSC) failed to fulfill its duty as primary body “for the maintenance of international peace and security”, the international community reacted with the development of the concept of Responsibility to Protect (R2P). It challenges the traditionally strong position of state sovereignty in international affairs, by including an obligation for each state to fulfill its primary responsibility as sovereign state, which is to protect their citizens. Parallel to the theoretical discussions, the first test-case for the concept of R2P emerged in Sudan’s western region Darfur. Civil war broke out in Darfur in April 2003, and has cost more than 300,000 lives, and almost three million people have been displaced. Once again the UNSC was not able to prevent mass atrocities against civilians. This book answers the question, why the UNSC failed in its task and what needs to be done for being able to fulfill its duty as international peace keeper in the future.