Recent years have seen an increased focus by the United Nations on questions of transitional justice and the rule of law in conflict and post-conflict societies,yielding important lessons for our future activities. Success will depend on a number of critical factors, among them the need to ensure a common basis in international norms and standards and to mobilize the necessary resources for a sustainable investment in justice. We must learn as well to eschew one-size-fits-all formulas and the importation of foreign models, and, instead, base our support on national assessments, national participation and national needs and aspirations. Effective strategies will seek to support both technical capacity for reform and political will for reform. The United Nations must therefore support domestic reform constituencies, help build the capacity of national justice sector institutions, facilitate national consultations on justice reform and transitional justice and help fill the rule of law vacuum evident in so many post-conflict societies.