‘Triggered by the North American Free Trade Agreement (NAFTA), Canada, the United States and Mexico redefined their public policies to facilitate the regionalization of transactions. However, this volume addresses the institutional gaps that still remain focusing mainly on the cross-border governance of security aspects. It gathers interdisciplinary contributions of specialists working on continental issues within Canada, the United States and Mexico and highlights the transnational dimension of certain issues still managed under national-framed policies. Furthermore, it explores the possibilities and constraints for moving public policy into new cross-border governance strategies. Divided in three parts, the first part assesses what is at stake in cross-border governance issues and whether the integrative trend in the region will be maintained or stalled in the years to come. The second part explores the growing scope of security problems interconnected with borders, migration, energy and drug trafficking across the region. It highlights how Mexico and Canada are responding or adapting their policy choices to a continental security approach framed by the US after the terrorist attacks of September 11, and to the major concerns of the Obama administration. The third part focuses on the governance of territorial borders and bilateral affairs, i.e. Mexico-US and Canada-Mexico relations.