Traditionally, public international law focused on the legal relations between sovereign states. However, since the end of World War II, significant developments, such as the codification of universal human rights, the emergence of international criminal law, or the acceptance of fundamental norms constituting jus cogens, gave rise to a value based approach to public international law. In this perspective, the international society is conceived as a community with common values, and the international legal order is characterized by an emergent “constitutionalization.” Against this background the project attempts to identify standards of public international law for legitimate governance in weak and failing states. The underlying presumption is that international law increasingly regulates the way state power is exercised internally because the common values permeate not only inter-state relations, but also intra-state situations, i.e. the relationship between the state and non-state actors, and relations between the latter.