Originally designed as a strictly defensive military alliance, the North Atlantic Treaty Organization's role has evolved and broadened in the years since the Cold War. This chapter first reviews the history of NATO's understanding of conflict resolution and conflict management (CR/M), analyzing how the Alliance's strategic conception of its non-collective-defense functions has evolved from a vague awareness of the threats arising from phenomena such as state collapse into a fully comprehensive doctrine. It then discusses the items in NATO's expansive conflict management toolbox, one that includes a comprehensive range of political, civilian, and military measures as well as effective coordination procedures. Finally, it focuses on Ukraine as an example of what NATO can – and cannot – do during the different phases of the modern conflict cycle, reviews the Alliance's contributions to Ukrainian security sector reform, and concludes that political will is the essential ingredient in any successful CR/M effort.