When the United Nations (un) agreed on a definition of the Responsibility to Protect (r2p) at the 2005 World Summit, the two paragraphs it endorsed articulated what r2p stands for, giving the concept a focused but narrow remit around protecting populations specifically from genocide, war crimes, ethnic cleansing and crimes against humanity in armed conflict. In its next paragraph, the un Membership reiterated concerns on the impact of armed conflict on children echoing the landmark 1612 Resolution by the Security Council on Children and Armed Conflict (caac) adopted a few weeks before. Though side-by-side in the text, caac and r2p were not linked. To this day, for international practitioners in emergency responses, the interaction between both remains unclear. While this simultaneous peak moment for r2p and caac may have occurred by chance, this article describes how both concepts (as advocacy tools and instruments for practitioners to ‘respond’) emerged out of similar concern for protecting civilians – including children – in conflict. However, the link between both concepts should not be overstated. While r2p and caac fit together for the intentions they share, this happened more coincidentally than purposefully. This article argues, taking an international practitioner’s perspective, that both concepts should not be understood as always operating at the same level. caac has grown from an advocacy platform to an umbrella of different programmes, responses, tools and frameworks, including the Monitoring and Reporting Mechanism (mrm) on Children and Armed Conflict. Even if applied with variable success, these tools and approaches under the caac agenda chart some ways practitioners can hope to do more towards protecting children in conflict. But for those same practitioners, delivering on a Responsibility to Protect is a different question – one where their ‘responsibility’ is at best secondary and implicit, because r2p sits squarely as a primary and explicit responsibility of states – who are also the ultimate duty bearers for children’s rights. While the echoes of a child rights agenda can be heard in the conversation around r2p, and while r2p can help frame and drive efforts by child protection practitioners to respond to some of the worst situations children face, r2p is, for the protection agency field officer, an aspirational goal, necessarily out of reach.