||Security is a core function of every legal order. In international relations, security is particularly difficult to achieve. International law is designed to make a decisive contribution to ensuring security, but it cannot always live up to expectations. During the last decade international law has been confronted with dramatic security challenges, such as ethnic conflicts, terrorism, or the proliferation of weapons of mass destruction. Syria, Iran/Israel, Libya, Kosovo, Guantanamo, Kundus are shorthand designations of larger legal issues, such as the meaning of 'responsibility to protect' and of 'human security', preventive self-defence, unilateral interpretation of Security Council resolutions, secession, the concepts of war or armed conflict, targeted killing and detention. The course should give students a deeper understanding of the content, development and context of the applicable international law.