 Finally, some argue that the enormous power disparities among states, combined with the absence of centralized and effective enforcement mechanisms, pose a systemic obstacle to the realization of the rule of law (Posner 2009). It is an open question to what extent the proliferation of discrete international legal regimes, e.g., relating to trade, human rights, with associated adjudicatory mechanisms, e.g., World Trade Organization, regional human rights courts such as the European Court of Human Rights or the Inter-American Court of Human Rights, begin to address this problem.