This conclusion presents some closing thoughts on the concepts covered in the preceding chapters of this book. The book sets out to study security community building below and beyond the level of states and international organisations. It focuses on the everyday practices of professionals from key security and foreign policy institutions. The communities of practice are the most effective way to develop practices of trust and peaceful conflict resolution among national security and foreign policy professionals. Through development of implicit common classification of problems at stake, as well as doing something in new way among the members of groups that share the same habitus, the 'shared practical can evolve through social interaction even though actors' understandings of self and other(s) might be unaltered'. The reach of regional communities of practice is mediated by the position its national members have in the national level security field.