Efforts to “operationalize” the Responsibility to Protect (R2P) continue to encounter resistance from key member states. Where it matters most, among vulnerable civilian populations caught up in war, the R2P appears to be making scant difference. Rising geopolitical tensions have added to a growing sense of pessimism among R2P advocates. Unsurprisingly, the most contentions aspect of the R2P concept continues to revolve around the question of the use of force for humanitarian purposes. It is a subject on which states, for an admixture of historical and political reasons, remain deeply divided. Nonetheless, as a politically significant norm, the R2P has come to command growing support from states, even though the degree to which the R2P norm has been truly internalized across international society varies greatly.