This volume traces the developments in the laws and practices of the European Union and five of its Member States (the United Kingdom, Germany, France, the Netherlands, and Italy) at two points in time: first at the time of the Gulf War following Iraq’s invasion of Kuwait in August 2000; secondly, following the terrorist attacks in the United States on 11 September 2001. The focus is on the legal status of immigrants and asylum seekers and how that legal status is being modified on grounds of security-related measures adopted over a period of about ten years. Particularly, the question is whether and how far situations have come into existence, which could be considered to be in conflict with fundamental principles of human rights.