its own people -- one that is absolute, unconditional, and continuing -- not to perpetrate or allow atrocity crimes on its territory (what we now call 'Pillar I'). The second responsibility is that of others in the international community -- including other states and intergovernmental organizations -- to assist states to discharge that primary responsibility, if they are willing to be so assisted ('Pillar II'). The third responsibility is that of others -- if prevention fails, and a state is manifestly failing to protect its own people -- to then provide that protection by every means prescribed, and circumscribed, by the United Nations Charter ('Pillar III'). The third dimension of R2P involved dramatically broadening the range of responses . Whereas the right to intervene, or humanitarian intervention, focused one-dimensionally on military reaction, the responsibility to protect involves multiple elements in the response continuum: preventive action, both long and short term; reaction when prevention fails; and post-crisis rebuilding aimed again at prevention, this time of recurrence of the harm in question. The 'reaction' element, moreover, was itself a nuanced continuum, beginning with persuasion, moving from there to non-military forms of coercion of varying degrees of intensity (like sanctions, or threat of international criminal prosecution), and only as an absolute last resort -- after multiple criteria were satisfied -- contemplating coercive military force. Articulated this way, R2P had an extraordinarily rapid take-up, almost unprecedented in the history of ideas. Within four years, in 2005, after some intense and sustained, and often cantankerous,