The Conclusion draws on the findings of the book to analyse the main implications of a reciprocity-based understanding of belligerent reprisals. First, it distinguishes this formalization of belligerent reprisals from earlier theories stressing the law-making function of the measure. Then, it accounts for the continued relevance of belligerent reprisals even at a time when mechanisms monitoring and enforcing compliance with the laws of armed conflict gain momentum. Finally, it explains how a reciprocity-based interpretation of belligerent reprisals would affect follow-up reform of the mechanism – be it in the sense of fine-tuning its regulation, or in the sense of disposing of it altogether.

The final substantive chapter of the book looks at how all these rules are implemented and enforced, and what mechanisms exist to hold violators of the law accountable for their acts. Common Article 1 of the Geneva Conventions requires states to ‘ensure respect’ for the rules of IHL, which is achieved through a range of measures such as education of the armed forces and civil society in the rules of IHL and entrenching the rules in domestic legislation. The chapter describes the roles of the ICRC, Protecting Powers and the International Humanitarian Fact-Finding Commission. The development and content of international criminal law are examined, including individual responsibility for war crimes, lesser violations of IHL, crimes against humanity and genocide, and the concept of command responsibility is explained. The growth in international and hybrid criminal tribunals is noted, as well as the roles played by the United Nations and other organisations in encouraging adherence to the rules of IHL. Finally the chapter examines mechanisms for implementation, enforcement and accountability in non-international armed conflict.

This chapter reviews the enforcement of IHL through a range of legal and non legal mechanisms. It first addresses the obligation to respect and ensure respect for IHL, protecting powers, the international humanitarian fact finding committee and the role of human rights bodies. State responsibility, state immunity and acts of state and political question doctrines are then discussed. Reparations, including state reparations, individual reparations and reparations by armed groups are then reviewed. UN immunity, UN enforcement and responsibility in peacekeeping operations, liability and reparations in peacekeeping operations and criminal responsibility in peacekeeping operations are also addressed. The use of belligerent reprisals in the enforcement of IHL and armed groups and enforcement of IHL is then discussed. In conclusion the chapter considers United Nations Action in enforcement of IHL.