The right to conscientious objection to military service is based on the International Covenant on Civil and Political Rights, and jurisprudence of the Human Rights Committee. This publication presents this legal framework, as well as jurisprudence of regional courts and commissions, in detail. It analyses important topics, such as selective conscientious objection to particular wars, conscientious objection for those who have volunteered to serve in the armed forces and conscientious objection for those in the reserves. For persons conscripted into the armed forces, it also develops issues relating to their right to know their rights in due time, applicable procedures, decision-making processes and the requirements of a fair and impartial procedure. The publication presents the law and practice of States in implementing the right to conscientious objection and organizing alternative service. It also covers the protection of conscientious objectors in international refugee law.