In March 2011, the UN Security Council authorized the use of force to protect civilians in Libya. This was the first time that the Council has ever authorized the invasion of a functioning state for such purposes. International society's relatively decisive responses to recent crises in Côte d'Ivoire and Libya has provoked significant commentary, suggesting that something has changed about the way the world responds to violence against civilians. Focusing on these two cases, this article examines the changing practice of the UN Security Council. It argues that we are seeing the emergence of a new politics of protection, but that this new politics has been developing over the past decade. Four things are new about this politics of protection: protecting civilians from harm has become a focus for international engagement; the UN Security Council has proved itself willing to authorize the use of force for protection purposes; regional organizations have begun to play the role of ‘gatekeeper’; and major powers have exhibited a determination to work through the Security Council where possible. However, the cases of Côte d'Ivoire and Libya also help to highlight some key challenges that might halt or reverse progress. Notably, states differ in the way they interpret mandates; questions are being asked about the UN's authority to act independently of specific Security Council authorizations; the overlap of regional organizations sometimes sends conflicting messages to the Security Council; and there remains a range of difficult operational questions about how to implement protection mandates. With these in mind, this article concludes with some suggestions about how the future challenges might be navigated in order to maintain the progress that has been made in the past decade.