A lovingly curated collection by well-established contributors marks a fitting tribute to both a definitive treaty, the United Nations Convention on the Law of the Sea (UNCLOS), and a definitive international law practitioner, Tommy Koh whose career highlights beyond those noted in this book include co-chairing the drafting of the ASEAN Charter and being Singapore’s permanent representative to the UN.

After a historic contextualization of UNCLOS and the pragmatic idealist, Koh, Chapters 2 to 5 review UNCLOS institutions. Lodge (Chapter 2) commences with the legal regime of the Area, while Jesus (Chapter 3) reflects on UNCLOS’s compulsory dispute settlement mechanisms, spotlighting the International Tribunal for the Law of the Sea. Kaye (Chapter 4) explores the Commission on the Limits of the Continental Shelf’s adaptation as the architectural support to extended continental shelf claims. Finally, Davenport (Chapter 5) examines the Meetings of the State Parties to the Convention as a cooperation and coordination forum for institutions.

Chapters 6 to 7 address the UNCLOS Implementing Agreements. First, Ridings threads together key elaborations provided by the UN Fish Stocks Agreement, while Mossop explores their functions, particularly the Agreement on Marine Biodiversity of Areas beyond National Jurisdiction.

Part III focuses on the marine environment—both preservation and evolution. Lost-Sieminska (Chapter 8) catalogues how the International Maritime Organization practices breathe life into the UNCLOS; Kojima (Chapter 9) demonstrates UNCLOS’s integration of environmental principles; and Liu and Lim (Chapter 10) suggest UNCLOS could, but currently does not, address key planetary challenges for contemporary life on Earth. The essays of Schofield (Chapter 11) and Stephens (Chapter 12) reflect on the manner in which the law of the sea can address climate change-related impacts, such as sea-level rise and entitlements (passive adaptation) or carbon dioxide absorption and ocean transformation (proactive responses necessary).

Shifting to dispute settlement, Wolfrum (Chapter 13) raises procedural hurdles in protecting community interests (suggesting advisory opinions offer better results), while Koroma (Chapter 14) promotes the conciliation method following the Timor-Leste/Australia Conciliation successes. Finally, Treves (Chapter 15) identifies harmonious trends in UNCLOS jurisprudence, followed by Klein and McNally (Chapter 16) assessing the different shades of subsequent State compliance.

Southeast Asia and the UNCLOS is the theme of Part V, ranging from Oegroseno (Chapter 17) spotlighting Indonesia’s contributions to the archipelagic State regime, to Thao’s (Chapter 18) grim assessment of regional fisheries management. Beckman (Chapter 19) contextualizes the laws of piracy, armed robbery and unauthorized boardings within Southeast Asia.

Finally, personal reflections kickoff with Jacobsson (Chapter 20) delving into UNCLOS’s resilience and ongoing challenges. Hoffmann (Chapter 21) attributes resilience to flexibility, institutional balancing, and the recognition of when supplementing practice is necessary. Oral (Chapter 22) poignantly reflects on revolution—both in UNCLOS’s contributions and in the environment in which UNCLOS must now operate. Jayakumar (Chapter 23) offers a touching tribute to Koh, including their enduring relationship and the UNCLOS negotiating process. Koh’s commemorative speech, delivered at the UN General Assembly in 2022, rounds off this volume. Sadly, by 2025, the challenges to peace, sovereign equality and international cooperation, which Koh critiqued, have only become further exacerbated including increased imperialism.