It is difficult to find a book on compliance that would not refer to Louis Henkin's How Nations Behave, citing his classic observation: “Almost all nations observe almost all principles of international law and almost all of their obligations almost all of the time.” A second disciplinary observation by Henkin is a bit less well known: “The student of law and the student of politics … purport to be looking at the same world from the vantage point of important disciplines. It seems unfortunate, indeed destructive, that they should not, at the least, hear each other.” Together, these two quotes point directly to the core of this book. Law and Governance in Postnational Europe: Compliance beyond the Nation-State discusses the sources of compliance and non-compliance with legal rules. It originated from an interdisciplinary project that involved both vantage points: law and politics.

And it took its time. Back in 1997, Christian Joerges, a lawyer focusing in his research on European and international economic law, asked Michael Zürn, a political scientist focusing on international relations, to join the Center for European Law and Policy (ZERP) at the University of Bremen. Since then we have been continuously engaged in comparing and discussing the perception of law by legal and political science. That co-operation led to a project submitted to the Deutsche Forschungsgemeinschaft (DFG) as part of the program on Regieren in Europa (Governance in Europe). The funds we received were used to bring Jürgen Neyer and Dieter Wolf on board this project.