This study traces the buildup and transformation of border control along the external frontiers of the EU from 1990 to 2001, in response to new perceived threats such as irregular migration, drug trafficking and transnational organized crime. Contrary to claims often made in the globalization literature, it argues that borders are not declining but rather gaining in importance, at least from a policing perspective. The study shows that in current border enforcement policies, police and military functions and characteristics are increasingly blurred. While military forces have become increasingly involved in border and immigration control, police forces active in this area have taken on military characteristics. Moreover, intermediary security forces have emerged as the predominant agencies on the border. The study also demonstrates the obsolescence of the classical linear conception of the border, in that border enforcement measures are increasingly targeted inward from and beyong the borderline