A current topic of global justice is the debate over the right of humanitarian military intervention or, as some style it, the “responsibility to protect” the “human security” of all, especially where that security is threatened by the very sovereign power charged to defend it. Such intervention came into its own only in the decade of the Nineties. This essay analyzes the factors that favored that outcome and sketches the difficulties to which humanitarian intervention proved to be exposed. There can be no doubt that the rhetoric supporting such a policy has expanded greatly during the past generation. But what of the reality? Is the “responsibility to protect” likely to prove the wave of the future, or merely that of the (still very recent) past?