The 2010 Kampala Review Conference raised challenges for the Obama administration’s  reengagement with the International Criminal Court. The authors—  leaders of the U.S. Kampala delegation—assess the treaty amendments adopted  by the states parties. Those amendments could, after January 2017, enable the  Court to exercise jurisdiction over the crime of aggression. As that period  approaches, the authors consider key issues regarding the definition and nature  of the crime, complementarity, state consent, the role of the Security Council,  the conditions for amending the Rome Statute, and how best to prevent the  important new jurisdiction over the crime of aggression from perversely chilling  legitimate uses of force.