“Courts crossing borders" was chosen as a title to convey the convergence of two realities in international politics. The first is that the traditional meanings of national sovereignty and, indeed, possibly the nation-state itself, are undergoing a radical metamorphosis. Simultaneously, the international political sphere is becoming progressively "judicialized.” By judicialization, we refer to a process explained by Torbjorn Vallinder as the "infusion of judicial decision-making and of court-like procedures into political arenas where they did not previously reside.” In some instances this process extends beyond formal courtroom proceedings and judicial deliberation and has come to dominate "nonjudicial negotiating or decision-making arenas by quasi-judicial (legalistic) procedures." This book addresses that phenomenon at the transnational level, where courts or court-like bodies have encroached not only on what has typically been seen as the political sphere, but also on traditional notions of the nation-state and national sovereignty.

The judicialization of international politics has resulted from the creation of a growing number of transnational organizations whose aims are to promote economic or political integration or to protect human rights. These organizations have challenged notions of exclusive sovereignty "as control over population within a well-defined territory" because of concerns over "the implications on state action or inaction" on a range of issues. The state, as a result, no longer is the primary actor in international relations, and "transnational, as opposed to interstate, relations have increased in importance." The list of transnational organizations is long, and many of them have a tribunal of some sort embedded within them. These include the European Union, with its Court of Justice (ECJ), and the European Council, with its European Court of Human Rights (ECHR). There is also the Inter-American Court of Human Rights for the Organization of American States (OAS), and even the North American Free Trade Agreement (NAFTA) provides for bi-national panels. There are courts for the World Trade Organization (WTO), the Asian Free Trade Area (AFTA), and the Common Market of the South (MERCOSUR), as well as courts created to address a specific international issue, such as the International War Crimes Tribunal for Rwanda (ICTR) and the International War Crimes Tribunal for the Former Yugoslavia (ICTY). Perhaps the most ambitious is the newly created International Criminal Court that named its 18 judges early in 2003. Whereas each of these courts possesses the capability to judicialize international relations and to erode national sovereignty, assertions of "universal jurisdiction" for human rights violations represent the most extreme threat. Universal jurisdiction possesses the potential to transcend or even obliterate protections traditionally afforded by national sovereignty for those accused of crimes against humanity.