The attacks of 11 September 2001 and the reaction to them has been the gravest challenge to date to the Human Rights Act 1998. The Antiterrorism, Crime and Security Act 2001 has expanded the remit of the Terrorism Act 2000 and there has been a new concentration on antiterrorism by government. This article assesses the impact of human rights law on the debate about liberty and security following 11 September. It considers how the provisions of the Human Rights Act have influenced the formulation and interpretation of anti-terrorism laws, and examines the role of the judiciary in adjudicating on disputes between the individual and the state. It ends with some general discussion about the security-driven challenges to human rights that lie ahead.