This insightful book provides an analysis of the central ethical issues that have arisen in combatting global terrorism and, in particular, jihadist terrorist groups, notably Al Qaeda, Islamic State and their affiliates. Chapters explore the theoretical problems that arise in relation to terrorism, such as the definition of terrorism and the concept of collective responsibility, and consider specific ethical issues in counter-terrorism. The book discusses a range of key topics including targeted killing, enhanced interrogation of terrorists, preventive detention, freedom of expression and terrorist content on social media, bulk metadata collection and responding to terrorist attacks that use weapons of mass destruction. It also explores ethical issues that have often been neglected, such as psychological warfare and stings. Taking a practical approach, the book offers recommendations for resolving these ethical problems in counter-terrorism. Integrating philosophical and legal analysis with empirical evidence, this book will be critical reading for scholars and students of human rights, international relations and terrorism and security law. Its use of specific examples of terrorist organisations, tactics and outcomes will also be valuable for policy-makers in the field.