As noted by other contributors to this roundtable, the response of the international community to civilian deaths in Libya--and the threat of further mass atrocities--is unusual in two key respects. First, Security Council Resolution 1973 authorized "all necessary measures" to protect civilians without the consent of the "host" state. The Council's intentions, and actions, could not be interpreted as anything other than coercive. Second, in contrast to other crises involving alleged crimes against humanity (most notably Darfur), diplomacy produced a decisive response in a relatively short period of time. Both of these features suggest that many analysts of intervention (including myself) need to revise their previously pessimistic assessments of what is possible in contemporary international politics. What is less clear, however, is how the crisis in Libya--and NATO's ongoing aerial campaign--will affect the fortunes and trajectory of the principle of the responsibility to protect (RtoP). There is much wisdom in Thomas Weiss's statement that today "the main challenge facing the responsibility to protect is how to act, not how to build normative consensus." (21) As I will suggest later, there have been costs to the current secretary-general's diplomatic strategy for building support for RtoP, which has placed great emphasis on so-called root-cause prevention and state capacity building. At the same time, it would be too rash to conclude that the Libyan case ends the debate over RtoP's status, meaning, and strength in contemporary international society. Indeed, the very fact that Resolution 1973 mentions only the "responsibility of the Libyan authorities to protect the Libyan population" and not the responsibility of the international community suggests that the latter notion was still contested by some members of the Security Council as an appropriate rationale for military action.