Robert Kolb explores the field of international humanitarian law through questions – which are at times challenging and controversial – in order to get to the very essence of the subject and give a fresh perspective. The result is an exposition both of the law as it stands, through its written and unwritten rules, and also of the uncertainties, gaps, controversies and practical problems which have arisen. IHL is revealed as a living tool, an ever-adapting means to an ever-remaining need of protection during times of armed conflict. Reflecting on current questions regarding the structure of the law, this concise and readable book offers a thought-provoking view of the system as a whole and its practical working. It covers the main principles, applicability issues and implementation of humanitarian law, as well as shedding light on the challenges ahead.