Can war be morally justified? What is the philosophy behind armed conflict? How do you conduct an ethical war? And what guides military action as the nature of conflict changes over time? Based on a MOOC (Massive Open Online Course) designed for both military personnel and non-specialists across the globe, Key Concepts in Military Ethics is structured as a series of ‘mini-chapters’ that cover a huge range of topics and issues: moral dilemmas, military and civilian interactions, freedom of the press, peacekeeping, terrorism, and humanitarian intervention. Written by a team of academic experts, many with military experience, the book contains scenarios and case studies, including the Gulf War, the Falklands War, ‘Ground Zero’ in New York City and more conventional theatres of war through history, as well as cyber-terrorism, the role of military contractors and unmanned weapons systems.