UN Charter Art.33 points to means such as negotiation, mediation and arbitration to settle disputes and to avoid the risk of use of force. Judgments of the International Court of Justice are of great value also to further develop international law. However, courts are hardly ever employed to save peace by the judicial settlement of big disputes. Following the precedent of the Nuremberg tribunal, special tribunals have been set up to try war crimes. Even more important, an international criminal court has been established. Fact-finding (termed ‘enquiry’) has achieved a prominent role both to solve and to prevent conflicts. Thus, the safeguards system of the IAEA using inspectors, cameras and satellites and environmental sampling continuously verifies that no fissionable material is diverted away from peaceful uses. With much fake news around, impartial professional inspection, monitoring and reporting – for instance, about the use or possession of chemical weapons – has become more important. Diplomacy seeks to secure or create peaceful relations by agreement, precluding or removing the threat or use of force. Examples are given of successes of diplomacy to preserve peace as well as of failures and of talks going forever without result.

Chapter 4 delves into the practice of the international judiciary and, specifically, international war crimes tribunals and the International Court of Justice (ICJ). By analysing the approaches of post–World War II tribunals, the committee established to review the 1999 NATO bombing campaign in the Former Yugoslavia, the Special Court for Sierra Leone, and the International Criminal Court, the first part of the chapter reflects on the conceptual, normative, and practical limitations of international criminal law. The second part provides a critical reading of two important ICJ cases, the Nuclear Weapons Advisory Opinion and the Armed Activities case (Congo v. Uganda), dealing respectively with the ecological devastation of nuclear weapons and pillage of natural resources in the Congo. The chapter ultimately contends that international justice, both in its criminal and inter-state dimensions, is concerned about individual/state agency, quantifiable harm, and its proximate causes. Thinking in these narrow terms about the ecological impacts of militarism and resource extraction associated with conflict fails to grasp the structural dimensions of the problem, the plurality of actors involved, and the obligations owed to other human and non-human beings.