It has become trite to claim that the increasing attention to post-conflict reconstruction and the creation of international administrations to oversee this process has resulted in a "legal void" in the transition from war or conflict to peace. The author will challenge this idea. The article will particularly focus on the suggested normative implications of the use of international territorial administration as a post-conflict reconstruction device. It will more specifically focus on the legal authority in post-conflict situations and on the existing rules on responsibility for post-conflict reconstruction, namely the laws of occupation and the role of the Security Council. The author will then discuss the adequacy and usefulness of existing conceptions of jus post bellum as a legal notion.