The urban treatment of human trafficking as “public problem” represents an emblematic policy case to explore the controversies of the new “European spatial politics of social protection”. Cities emerge as spaces of “unbounding” by which practices of internationalization of welfare delegitimize national “law enforcement” boundaries. “Policy entrepreneurs” – governmental, intergovernmental and non-governmental organizations, faith organizations, unions, etc - working against human trafficking within the framework of “internationalization”, challenge conventional ways by which we are accostumed to think about the “public” and democracy. The comparison between two urban initiatives in USA And EU intends to highlight the times, the contents and the modalities by which coalitions of “policy entrepreneurs” integrate welfare and security policies against human trafficking and make different trade-off between standardization and innovation emerge. Relevance of the project (1) To enrich the debate on the formation of a European social solidarity model overcoming the relationship citizenship/sovereignty/territorialiy; (2) to improve policymaking and urban research. Objectives (1) to detect intersectoral effects of targeted actions on vulnerable groups and the different forms of enactment of actors and resources by which the problem is treated as “local”; (2) to define and transfer integrated knowledge frameworks on the regional effects of the internationalisation of welfare, and thereby, on the changing nature of the “public” of social policy; (c) to develop a frontier-research profile capable of encouraging innovation and regional cooperation as well as producing innovative “transdisciplinary” arrays of knowledge on “cities” and “territories”, beyond conventional approaches based on the dualism urban(place)/social (people). Research methodology Comparative case study; Ethnography, Direct Participant Observation and complementary qualitative tools