Territorial borders are inextricably connected with questions of security. ‘Saviours or sinners?’ explains how the challenge of controlling the movement of people and goods across borders is formidable, with numbers of migrants increasing every year. The actual security implications of migration are mixed and often politically polarizing. For individuals, the security benefits lie in escaping political persecution, war, or famine, or in improving one's economic position. Receiving states may see immigration as an opportunity to solve problems of skills shortages. Most contentious in debates about migration, however, is the extent to which large influxes of people can raise difficult questions about the integration of new arrivals into the broader society.