Nowadays, countering terrorism involves many pressing ethical dilemmas for the professionals involved. The terrorist attacks on 11 September 2001 have had a tremendous impact on the practice of... Show moreNowadays, countering terrorism involves many pressing ethical dilemmas for the professionals involved. The terrorist attacks on 11 September 2001 have had a tremendous impact on the practice of counterterrorism. The option of shooting down a presumed hijacked commercial airliner, with the deaths of many innocent passengers as a consequence, has been added to the toolbox of counterterrorism professionals. Naturally, most of the ethical dilemmas faced by counterterrorism professionals are not as extreme as this and mostly related to routine issues.Most of the ethical dilemmas facing counterterrorism professionals were, when this research started, hardly represented in the literature on counterterrorism and security studies, or in studies on applied ethics and ethics support. This thesis sets out to fill this gap by formulating and then addressing its main research question: What is the current relevance of the ethics of counterterrorism and what is the added value of ethics support within the practice of counterterrorism? This thesis contributes to the debate on the ethics of counterterrorism and explores the added value of applied ethics and ethics support in professional practice. Show less