In response to two conflicts in the 1990s - the Yugoslav wars of dissolution and the Rwandan genocide of 1994 - the United Nations (UN) UN Security Council created the International Criminal Tribunals for the Former Yugoslavia and Rwanda (ICTY and ICTR). This chapter begins with the creation of the ICTY through UN Security Council Resolution 827, the court’s three organ structure (Registry, Office of the Prosecutor, and Chambers), jurisdiction, and relationship with national courts. The chapter examines the milestones of the ICTY, from its first case through to the conflict in Kosovo, prosecution of former Heads of States, and implementation of its Completion Strategy, and assesses the critiques of the tribunal. The chapter then turns to the history of the creation of the ICTR, its structure (which was similar to that of the ICTY), and its jurisdiction. It then examines the practice of the ICTR, from its initial troubles through the prosecution of the leaders of the genocide, and the implementation of its Completion Strategy. Both Tribunals have now closed and transitioned into a residual phase.

The chapter explains the principles of inter-state cooperation in criminal matters in connection with domestic proceedings. It sets out the international legal framework governing criminal law cooperation among states, including multilateral and bilateral agreements of general application and treaties specifically concerning international crimes, most notably the 2023 Ljubljana–The Hague Convention on International Cooperation in the Investigation and Prosecution of the Crime of Genocide, Crimes Against Humanity and War Crimes. The chapter sets out the differences between the traditional forms of assistance in criminal matters, which are associated with a higher degree of formality and subject to broader grounds for refusal and, on the other hand, the more advanced forms of cooperation (exemplified by mutual recognition in the European Union context) prioritizing effective enforcement while recognizing limited grounds to refuse requests. The chapter reviews the prerogatives of the requested states to refuse under these models with reference to double criminality, specialty, statutory limitations, ne bis in idem, and human rights concerns. It then takes a closer look at the traditional forms of cooperation and the issues which arise in that context, focusing on extradition, other mutual legal assistance, transfer of criminal proceedings, and enforcement of foreign penalties.

This chapter investigates the way in which international law treats reallocated private rights post delimitation. In doing so, it examines the various mechanisms which are available in international law for the accommodation of such rights on land and at sea, respectively. Firstly, the study compares the conventional mechanisms which are employed by states. Next, it compares the mechanisms which are employed in delimitation case law. A synthesis of the findings reached shows that the accommodation of reallocated private rights is more systematic and effective on land than in the ocean. This demonstrates that reallocated private rights have a greater chance of surviving on land than at sea.