In this chapter, Daniel Franchini and Russell Buchan examine the status, nature, content, and scope of the obligation of peaceful dispute settlement. This chapter traces the emergence of this obligation under customary and conventional international law, analyses the conditions that trigger its engagement, and explores what measures disputants must take in order to discharge this obligation. This chapter maintains that the peaceful settlement obligation is an interstitial norm insofar as it influences the interpretation and application of other rules of international law relevant to the peaceful settlement of disputes.

This chapter examines the interplay between Philip Jessup’s experience of the early years of the United Nations and the development of his scholarship, in particular his inclusive and pragmatic conception of ‘transnational law’. It is contended that Jessup’s UN experience informed writings that evince a practitioner’s feel for the role of diplomacy in the workings of international law, as well as aliveness to the possibilities of novel institutional forms and processes. The chapter goes on to apply Jessup’s scholarly insights to contemporary challenges of the UN, focusing on the Sustainable Development Goals. The achievement of the SDGs emerges as a thoroughly transnational challenge, requiring application and coordination of each of the strands of Jessup’s famous definition of ‘transnational law’.