In courts and tribunals, political arenas like the United Nations Security Council, and popular and scholarly journals, discursive recourse to the principle of proportionality has become frequent and vehement. It tends most audibly to arise in the midst of military conflicts pitting states against each other. But it also emerges in interstate trade disputes and when states, seeking to protect national security or public health, restrict internationally protected human rights.

Over the past few decades, regional human rights tribunals have grown in both number and activity. The European Court of Human Rights (European Court or ECHR) now receives tens of thousands of petitions and issues over fifteen hundred judgments on the merits each year. The Inter-American Court of Human Rights recently tripled the number of cases that it resolves annually. At the time of this writing, in mid-2008, Africa’s own regional human rights court, the African Court on Human and Peoples’ Rights, prepares to begin hearing its first contentious cases. Currently, sixty-eight states are subject to the decisions of the two established regional courts (forty-seven in Europe and twenty-one in the Americas), up from less than half that number twenty years ago. In the nascent African system, twenty-four African Union member states have ratified the Protocol establishing the African Court, with an additional twenty-five signatory states.