The UN Security Council is the central actor in matters of peace and security, but it is notoriously affected by the global political environment. Because of the veto power, it is currently unable to address crucial peace and security issues, such as the war in Ukraine. This introduction sets out the Security Council’s role in maintaining international peace. It offers an overview of how the Council’s institutional shortcomings have been addressed in the past. The chapter identifies four defining fields of tension in which the Security Council currently operates, which are explored throughout the remaining chapters of the book. These fields comprise the tensions between: (i) law and power; (ii) centralisation and institutional diversification; (iii) universalism and regionalism; and (iv) formalisation and informalisation. The chapter concludes with a short overview of the book’s main chapters.

The war launched in February 2022 by Russia against Ukraine has become a stress test for the role of the Security Council, and it confirms some findings of the three Trialogue authors. Congyan Cai, Larissa van den Herik, and Tiyanjana Maluwa have examined the manifestations of law and power in the Council, the substance and procedure of its workings, and the relationship between the Council as the centre and its periphery in the form of regional organisations. This concluding chapter revisits the three dichotomies in the light of the Russian invasion, asking: has power eclipsed law? Are empty ritualistic procedures unable to deliver substantive outcomes? And has the centre been disabled, so that peripheral actors dominate the scene? The chapter concludes that the Security Council remains important not only as a centre of power but also as a creature of law and as a law-producer. The Council’s action and inaction are highly dependent on legal procedures (as opposed to mere ‘politics’). Finally, the Council, also in its response to the Ukrainian war, is firmly embedded within a network of other international bodies and actors.