The fifth session of the Assembly of States Parties (ASP) has the potential to be a milestone in the evolution of the International Criminal Court (ICC). For the first time, states parties should have significant opportunities to discuss substantive aspects of ICC policy and practice at an ASP session. While scrupulously respecting the ICC’s independence, states parties must make the most of these opportunities in order to promote the court’s development as an institution that can achieve its mandate to bring perpetrators of the most serious crimes to justice when national courts are unable or unwilling to do so. In making the most of the opportunities for discussion, states parties will also increase their understanding of the court’s work and challenges, which will enable the ASP to more effectively exercise its functions. States parties must further take decisions at this ASP session to ensure that the ICC has necessary support and cooperation. The ICC has now moved more fully to an operational phase and it is actively in need of cooperation to conduct investigations and trials.