During the month of March 2013, some Belgian and Dutch police researchers gathered to discuss a trajectory for the study of the pluralisation of policing in European metropolises. We observed a significant amount of comparative work on different national police systems, but only a minor comparative focus on the local reality of European metropolises. According to United Nations UN Habitat, the growth of urban population was in 1970 only 37%, while the prospective for 2030 is 60%1. Benjamin Barber (2013) argues consequently that the future of global governance lies with cities, and the mayors who lead them. Is the concept of the metropolis becoming increasingly important to the detriment of the concept of the national state?