The phrase « Security Sector Reform » (SSR) crops up frequently in texts on crisis management and peacekeeping operations. Yet it is just mere words. It is not a concept, let alone a doctrine or an area of expertise. It is only a label that often presents a variety of significations. As a result, there is complete confusion as to its actual meaning. This article purports to dispel this confusion as much as possible, especially in a post-crisis context, and aims at examining SSR within a wider context: post-crisis security tasks.