SG-F-10: The International Law of the Sea — Tommy Koh and UNCLOS (1973-1982)

Document Code: SG-F-10 Full Title: The International Law of the Sea: Tommy Koh and the Third United Nations Conference on the Law of the Sea (1973-1982) Coverage Period: 1973-1982 Level Designation: Level 2 Deep Dive Primary Sources Consulted:

1. Tommy Koh, "A Constitution for the Oceans," remarks by the President of the Third United Nations Conference on the Law of the Sea, 6 and 11 December 1982, reproduced in The Law of the Sea: Official Text of the United Nations Convention on the Law of the Sea (New York: United Nations, 1983)
2. United Nations Convention on the Law of the Sea, opened for signature 10 December 1982, 1833 UNTS 397 (entered into force 16 November 1994)
3. Tommy Koh and Shanmugam Jayakumar, "The Negotiating Process of the Third United Nations Conference on the Law of the Sea," in Myron H. Nordquist (ed.), United Nations Convention on the Law of the Sea 1982: A Commentary, Vol. I (Dordrecht: Martinus Nijhoff, 1985)
4. Tommy Koh, The Tommy Koh Reader: Favourite Essays and Lectures (Singapore: World Scientific, 2013)
5. Tommy Koh, The Quest for World Order: Perspectives of a Pragmatic Idealist, edited by Amitav Acharya (Singapore: Times Academic Press, 1998)
6. Singapore Parliamentary Debates (Hansard), various sessions relating to maritime policy and the Law of the Sea, 1970s-1980s
7. S. Jayakumar, Diplomacy: A Singapore Experience (Singapore: Straits Times Press, 2011)
8. Robert Beckman and Clive Schofield, "Defining EEZ Claims from Islands: A Potential South China Sea Change," International Journal of Marine and Coastal Law 29, no. 2 (2014)
9. Lee Kuan Yew, From Third World to First: The Singapore Story 1965-2000 (Singapore: Times Editions, 2000)
10. Ministry of Foreign Affairs, Singapore, records and statements relating to UNCLOS, the Pedra Branca case, and maritime boundary agreements

Related Documents:

• SG-H-DPM-02: S. Rajaratnam — Foreign Minister and architect of Singapore's foreign policy
• SG-F-09: The Pedra Branca Case — sovereignty disputes and international adjudication
• SG-F-11: Singapore and ASEAN — multilateral diplomacy and regional order
• SG-F-27: Singapore and the Iran-Israel-US War — Hormuz Crisis and Governance Response (2025–2026) — Tommy Koh's 19 October 2025 Facebook post on the Gaza newborn named "Singapore" is cited as a primary source; freedom-of-navigation arguments inherit directly from UNCLOS

Version Date: 2026-03-08

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1. Key Takeaways

• Tommy Koh Thong Bee (born 12 November 1937) served as President of the Third United Nations Conference on the Law of the Sea (UNCLOS III) from 1981 to 1982, guiding the most complex multilateral negotiation of the twentieth century to its conclusion with the adoption of the United Nations Convention on the Law of the Sea on 10 December 1982 in Montego Bay, Jamaica.

• The Convention, which Koh himself called "a constitution for the oceans," established the comprehensive legal framework governing all uses of the seas and their resources — from territorial waters to the deep seabed — and remains the foundational instrument of international maritime law. It is one of the most significant treaties in the history of international law.

• Koh's appointment as Conference President was itself remarkable: a representative of a city-state of 2.5 million people, with no significant navy and only 700 square kilometres of land, was chosen to preside over a negotiation involving more than 160 states and touching upon some of the most contentious questions of sovereignty, resource allocation, and great-power competition in the Cold War era.

• Singapore's core interest in the Conference was freedom of navigation, particularly the right of transit passage through international straits — above all the Straits of Malacca and Singapore, through which a substantial proportion of global maritime trade passes. The Convention's regime for straits used for international navigation, codified in Part III, directly protected Singapore's existential interests as a trading nation and port city.

• Koh succeeded Hamilton Shirley Amerasinghe of Sri Lanka, who had served as Conference President from 1973 until his death in December 1980. Koh inherited a negotiation that had been running for nearly a decade, with several key issues still unresolved, and brought it to conclusion within two years through a combination of diplomatic skill, procedural innovation, and personal credibility.

• The negotiating process pioneered by UNCLOS III — consensus-building, package deals, informal consultations, and the avoidance of voting on individual articles — became a model for subsequent multilateral negotiations and represented a significant innovation in international diplomatic practice.

• The Convention's provisions on exclusive economic zones (EEZs), extending coastal state jurisdiction to 200 nautical miles, represented a fundamental redistribution of ocean wealth from maritime powers to coastal developing states, while the deep seabed mining regime (Part XI) proved so controversial that it had to be substantially modified by a 1994 Implementation Agreement before the Convention could enter into force.

• For Singapore, UNCLOS provided legal certainty on straits passage, a framework for maritime boundary delimitation with neighbours (Malaysia and Indonesia), and a mechanism for the peaceful settlement of maritime disputes — including the eventual referral of the Pedra Branca sovereignty dispute to the International Court of Justice.

• Tommy Koh's role at UNCLOS established him as Singapore's most prominent international lawyer and diplomat, and launched a subsequent career that included service as Ambassador to the United States (1984-1990), chairmanship of the preparatory committee for the 1992 Rio Earth Summit, membership of the International Law Commission, and appointment as a judge on the International Tribunal for the Law of the Sea.

• His career exemplifies a distinctive Singaporean approach to multilateral diplomacy: a small state earning influence not through military or economic power but through intellectual credibility, procedural competence, and the capacity to serve as an honest broker between competing blocs.

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2. The Record in Brief

The Third United Nations Conference on the Law of the Sea was convened in 1973 to negotiate a comprehensive treaty governing the world's oceans. It was triggered by a combination of factors: the 1967 speech by Malta's Ambassador Arvid Pardo to the UN General Assembly, declaring the deep seabed beyond national jurisdiction to be the "common heritage of mankind"; the inadequacy of the existing legal framework established by the 1958 Geneva Conventions on the Law of the Sea; the rapid expansion of coastal state claims to maritime jurisdiction in the 1960s and 1970s; and the broader decolonisation movement, which brought dozens of new states into the international system with demands for a more equitable distribution of ocean resources.

The Conference met in eleven formal sessions between 1973 and 1982, in locations including New York, Caracas, and Geneva. It involved more than 160 participating states organised into various negotiating blocs: the Group of 77 (developing countries), the Western European and Others Group, the Eastern European (socialist) bloc, the landlocked and geographically disadvantaged states, the archipelagic states, and the coastal states with long coastlines. Cross-cutting these were issue-specific coalitions — the "territorialists" who wanted expanded coastal state jurisdiction, the "maritime states" who prioritised freedom of navigation, and the "miners" and "anti-miners" on the deep seabed question.

Tommy Koh entered this arena as Singapore's Permanent Representative to the United Nations, a post he held from 1968 to 1971 and again from 1974 to 1984. He had been active in the Conference from its early stages and served as chairman of several negotiating committees. When Conference President Hamilton Shirley Amerasinghe of Sri Lanka died in December 1980, Koh was elected to succeed him — a testament both to his personal reputation and to the perceived neutrality of Singapore as a small state without a major stake in the most divisive issues (deep seabed mining and extended continental shelf claims).

Koh inherited a Conference that was close to exhaustion. Nine years of negotiation had produced a comprehensive Draft Convention, but several key issues remained unresolved, and the temptation to abandon the consensus approach in favour of voting was growing. The United States under President Ronald Reagan had announced a comprehensive review of the draft treaty, with particular objections to Part XI on deep seabed mining, which the Reagan administration regarded as antithetical to free-market principles. The Soviet bloc had its own reservations. Many developing countries feared that any reopening of settled issues would unravel the entire package.

Koh managed the final sessions with a combination of firmness and flexibility. He insisted on maintaining the consensus approach — the principle that the Convention should be adopted as a package deal rather than voted on article by article — while acknowledging that perfection was the enemy of the good. He conducted extensive informal consultations, shuttled between delegations, and used the authority of the presidency to resist attempts to reopen settled compromises. When it became clear that the United States would not join the consensus, Koh proceeded to a vote on 30 April 1982. The Convention was adopted by 130 votes to 4 (the United States, Israel, Turkey, and Venezuela), with 17 abstentions.

The Convention was opened for signature at Montego Bay, Jamaica, on 10 December 1982. In his closing remarks — the famous "Constitution for the Oceans" statement — Koh declared that the Convention represented "a monumental achievement of the international community, second only to the Charter of the United Nations." One hundred and nineteen states signed the Convention on the first day. It would take another twelve years, and a 1994 Implementation Agreement modifying the deep seabed mining provisions, before the Convention entered into force on 16 November 1994. As of 2026, it has been ratified by 169 parties, making it one of the most widely ratified treaties in history. The United States remains a notable non-party, though it regards most of the Convention's provisions as reflecting customary international law.

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3. Timeline of Key Events

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4. Background and Context

The Old Law of the Sea and Its Collapse

For centuries, the law of the sea was governed by a relatively simple framework: a narrow belt of territorial sea (traditionally three nautical miles) under coastal state sovereignty, and beyond that, the high seas — open to all for navigation, fishing, and other uses under the doctrine of freedom of the seas, most famously articulated by Hugo Grotius in Mare Liberum (1609). This framework served the interests of maritime powers, particularly the European colonial states and later the United States, which depended on freedom of navigation to project naval power and conduct global commerce.

By the mid-twentieth century, this framework was under severe strain. President Harry Truman's 1945 proclamation asserting US jurisdiction over the resources of the continental shelf set off a cascade of unilateral claims by coastal states. Latin American states, led by Chile, Ecuador, and Peru, claimed 200-nautical-mile zones of maritime jurisdiction — initially for fisheries protection but increasingly as assertions of sovereignty. The 1958 Geneva Conventions on the Law of the Sea attempted to codify the existing rules but left critical gaps: they failed to define the breadth of the territorial sea, and their continental shelf regime — based on the vague criterion of "exploitability" — threatened to extend coastal state jurisdiction across the entire ocean floor as technology advanced.

The second UN Conference in 1960 failed to resolve the territorial sea question by a single vote. Through the 1960s, the number of coastal states expanded dramatically as decolonisation brought dozens of new nations into the international system, many of which rejected the existing law of the sea as a relic of colonialism that served the interests of maritime powers at the expense of developing coastal states.

Arvid Pardo and the Common Heritage

The catalyst for UNCLOS III was Arvid Pardo, Malta's Ambassador to the United Nations, who on 1 November 1967 delivered a four-hour speech to the UN General Assembly's First Committee. Pardo warned that existing legal arrangements would allow technologically advanced states to appropriate the mineral resources of the deep seabed — particularly the manganese nodules rich in nickel, copper, cobalt, and manganese found on the floor of the Pacific Ocean. He proposed that the seabed beyond national jurisdiction be declared the "common heritage of mankind," to be managed by an international authority for the benefit of all states, with particular attention to the needs of developing countries.

Pardo's speech resonated powerfully with the Group of 77 developing countries and set in motion the process that would lead to UNCLOS III. The UN General Assembly established the Committee on the Peaceful Uses of the Sea-Bed and the Ocean Floor beyond the Limits of National Jurisdiction (the Seabed Committee) in 1968, and in 1970 adopted Resolution 2749, the Declaration of Principles Governing the Sea-Bed, which affirmed the common heritage principle. In 1970, the General Assembly also decided to convene a comprehensive conference on the law of the sea.

Singapore's Existential Interest: The Straits

Singapore's stake in the law of the sea negotiations was unlike that of most other states. Singapore was not primarily interested in claiming maritime resources — its tiny land area generated correspondingly minimal maritime zones. It had no significant fishing fleet, no offshore oil or gas, and no interest in deep seabed mining. Its interest was in one issue above all others: freedom of navigation, and specifically the legal regime governing passage through international straits.

The Straits of Malacca and Singapore are among the most strategically and commercially important waterways in the world. Connecting the Indian Ocean to the Pacific, they carry a substantial share of global maritime trade — including a large proportion of the oil shipped from the Persian Gulf to East Asia. For Singapore, a city-state whose economy depended entirely on trade and whose port was its economic lifeline, any restriction on the right of passage through these straits would be an existential threat.

The problem was that the traditional three-nautical-mile territorial sea had left a corridor of high seas through the Straits of Malacca, through which ships could pass freely under the doctrine of freedom of the seas. If the territorial sea were extended to twelve nautical miles — as virtually every state now supported — this corridor would disappear. The entire strait would fall within the territorial seas of Malaysia and Indonesia (and at the eastern end, Singapore). Under the traditional law of innocent passage through territorial seas, coastal states had significant powers to regulate and even suspend passage. For warships, submarines, and aircraft, the right of innocent passage was contested or non-existent.

This was unacceptable to the major maritime powers — the United States, the Soviet Union, and the European naval states — which needed to move their fleets through international straits without coastal state interference. It was equally unacceptable to Singapore, which needed to ensure that Malaysia and Indonesia could not use sovereignty claims over the strait to throttle Singapore's trade.

Singapore therefore found itself in an unusual alliance with the maritime powers on the straits issue, while remaining aligned with the developing world on most other questions. This cross-cutting position — combined with Singapore's small size and perceived neutrality — gave its diplomats, and Tommy Koh in particular, a degree of credibility as honest brokers that few other delegations could match.

Tommy Koh: Formation of a Diplomat-Scholar

Tommy Koh Thong Bee was born on 12 November 1937 in Singapore. He was educated at the University of Malaya (later the National University of Singapore), where he studied law, and at Harvard Law School, where he earned an LLM in 1966 and later a postgraduate diploma in criminology from Cambridge University. He joined the Faculty of Law at the University of Singapore in 1964, where he taught international law and developed the expertise in public international law that would define his career.

Koh was appointed Singapore's Permanent Representative to the United Nations in 1968, at the age of thirty, an exceptionally young appointment. He served in New York until 1971, when he returned to Singapore to become Dean of the Faculty of Law at the University of Singapore. He returned to the UN in 1974 for a second term as Permanent Representative, which lasted until 1984. It was during this second term that he became deeply involved in the Law of the Sea Conference and ultimately rose to its presidency.

Koh's intellectual formation combined legal rigour with diplomatic pragmatism. He was not a theorist of international law in the academic sense but a practitioner who understood that law, in the international sphere, is the product of negotiation and political compromise. His Harvard training gave him familiarity with American legal thinking and an ease with American diplomats that would prove valuable during the difficult negotiations with the Reagan administration. His background as a law professor gave him credibility with the legal advisors who staffed many delegations. His temperament — patient, courteous, persistent, and capable of enormous stamina during marathon negotiating sessions — suited him perfectly for the gruelling process of multilateral negotiation.

S. Rajaratnam, Singapore's Foreign Minister during much of this period, provided the strategic framework for Singapore's foreign policy — the emphasis on international law, multilateralism, and the rule-based international order as the small state's best defence against the law of the jungle. Koh was, in many respects, the operational embodiment of the Rajaratnam doctrine: using the tools of international law and multilateral diplomacy to advance Singapore's interests in ways that a small state's limited military and economic weight could never achieve alone.

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5. The Primary Record

5.1 The Architecture of UNCLOS III: Negotiating the Impossible

The Third United Nations Conference on the Law of the Sea was, by any measure, the most ambitious and complex multilateral negotiation ever attempted. It ran for nine years (1973-1982), involved more than 160 states, and sought to create a comprehensive legal framework for every aspect of human activity in the oceans — from the baseline of territorial seas to the deepest abysses of the ocean floor.

The Conference was organised around three Main Committees. The First Committee dealt with the international seabed area beyond national jurisdiction — the "Area" — and the regime for deep seabed mining. The Second Committee addressed traditional law of the sea issues: the territorial sea, the contiguous zone, the exclusive economic zone, the continental shelf, the high seas, landlocked states, and — critically for Singapore — the regime for straits used for international navigation. The Third Committee dealt with marine scientific research, protection of the marine environment, and technology transfer.

The Conference's most important procedural innovation was the "gentleman's agreement" adopted at its first substantive session in Caracas in 1974: the Conference would make every effort to reach agreement on substantive matters by way of consensus, and there would be no voting on such matters until all efforts at reaching consensus had been exhausted. This rule — which was not formally binding but was treated as sacrosanct for most of the Conference — was essential to the eventual success of the negotiation. It meant that no state could be outvoted on an issue vital to its interests, which kept all parties at the table. It also meant that the Convention would be a package deal: states would accept provisions they disliked on some issues in exchange for provisions they wanted on others.

The consensus rule also shaped the Conference's distinctive negotiating method: instead of formal committee debates and voting, the real work was done in informal consultations, "friends of the chair" groups, and corridor negotiations. The Conference Presidents and committee chairmen played a crucial role as mediators, drafting compromise texts that they put forward on their own authority and then seeking to build consensus around them.

5.2 The Key Substantive Issues

The Territorial Sea and Contiguous Zone. The Conference resolved the longstanding dispute over the breadth of the territorial sea by establishing a twelve-nautical-mile limit (Articles 3-4). This represented a compromise between states that had traditionally insisted on three miles and those that had claimed up to 200 miles. A contiguous zone of up to 24 nautical miles was also established (Article 33).

The Exclusive Economic Zone. Perhaps the most significant innovation of the Convention was the exclusive economic zone (EEZ), extending up to 200 nautical miles from the baseline (Part V). Within the EEZ, the coastal state has sovereign rights over natural resources — fisheries, oil, gas, and minerals — but not sovereignty. Other states retain the freedoms of navigation, overflight, and the laying of submarine cables and pipelines. The EEZ concept represented a grand bargain: developing coastal states got jurisdiction over the resources they demanded, while maritime states preserved the navigational freedoms they required.

Straits Used for International Navigation. For Singapore, Part III of the Convention was the most critical provision. It established the regime of transit passage through straits used for international navigation — a right that could not be suspended or hampered by the bordering states. Transit passage applied to all ships and aircraft, including warships and submarines (which could transit submerged), and to military aircraft. This was a stronger right than innocent passage through territorial seas, which could be suspended and which did not clearly apply to aircraft or submerged submarines.

The transit passage regime was the product of intense negotiation between the maritime powers (which wanted essentially unrestricted passage) and the strait states (particularly Indonesia and Malaysia, which wanted greater control). The compromise gave bordering states the right to designate sea lanes and traffic separation schemes, and to adopt laws and regulations relating to safety of navigation and pollution prevention, but not to impede transit passage itself. For Singapore, this regime was the Conference's single most important achievement — it guaranteed that the Straits of Malacca and Singapore would remain open to international shipping regardless of the territorial sea extension.

The Continental Shelf. The Convention defined the continental shelf as extending to the outer edge of the continental margin or to 200 nautical miles from the baseline, whichever was greater (Article 76). For states with broad continental margins — including some developing countries — this represented a significant expansion of jurisdiction. The Commission on the Limits of the Continental Shelf was established to review claims to extended continental shelves.

The Deep Seabed — Part XI. The most contentious issue of the entire Conference was the regime for the deep seabed beyond national jurisdiction — the "Area" — and its mineral resources, declared to be the "common heritage of mankind." The Convention established the International Seabed Authority (ISA) to manage mining in the Area, and created the Enterprise — an operational arm of the ISA that would conduct mining directly on behalf of the international community. Private and state mining companies would be required to operate under contract with the ISA, pay royalties, and transfer technology to the Enterprise.

This regime was anathema to the United States and other Western industrialised states, which regarded it as a form of international socialism that would discourage private investment, create an unwieldy bureaucracy, and redistribute wealth to developing countries through mechanisms that had no basis in market economics. The deep seabed issue would ultimately be the reason for the US refusal to sign the Convention, and it was the Part XI provisions that had to be substantially modified by the 1994 Implementation Agreement before the Convention could achieve near-universal participation.

Archipelagic States. The Convention created a new legal category — the archipelagic state — with the right to draw straight baselines connecting the outermost points of its outermost islands, enclosing the waters within as archipelagic waters (Part IV). This was primarily of interest to Indonesia and the Philippines, both of which had long claimed their inter-island waters as internal waters. The regime included a right of archipelagic sea lanes passage — analogous to transit passage through straits — to ensure that the enclosure of archipelagic waters did not impede international navigation.

Dispute Settlement. The Convention established a comprehensive system for the compulsory settlement of disputes (Part XV), including the International Tribunal for the Law of the Sea (ITLOS), arbitration under Annex VII, and special arbitration under Annex VIII. States parties could choose their preferred forum, but they were obligated to submit to binding third-party settlement. This was one of the most progressive dispute settlement provisions in any international treaty and would have significant consequences for maritime disputes in the decades to come — including in the South China Sea.

5.3 Koh's Presidency: Managing the Endgame (1981-1982)

Tommy Koh assumed the presidency of the Conference in March 1981 under exceptionally difficult circumstances. Hamilton Shirley Amerasinghe, the Sri Lankan diplomat who had guided the Conference through eight years of negotiation, had died in December 1980. The draft Convention was substantially complete, but several key issues remained unresolved, and the election of Ronald Reagan as President of the United States in November 1980 had introduced a major new complication.

The Reagan administration announced in March 1981 that it was conducting a comprehensive review of the draft Convention, with particular concern about Part XI. This review continued for over a year, creating enormous uncertainty. The developing countries, which formed the majority of Conference participants, feared that the US review was a pretext for reopening settled compromises and extracting further concessions. The Soviet Union and its allies had their own reservations about various provisions. The Conference was in danger of collapsing under the weight of competing demands and accumulated fatigue.

Koh's management of this endgame demonstrated several qualities that distinguished him as a negotiator. First, he maintained the integrity of the package deal. He refused to allow individual provisions to be reopened wholesale, while acknowledging that limited amendments to accommodate legitimate concerns might be possible. This was a difficult balance: too much rigidity would alienate the United States and its allies; too much flexibility would unravel the compromises that had taken years to achieve.

Second, he used the authority of the presidency to set deadlines and create momentum. He announced that the Conference would complete its work at the eleventh session in 1982, forcing delegations to make final decisions rather than continuing to negotiate indefinitely. This deadline pressure, combined with Koh's personal credibility, helped to concentrate minds.

Third, he conducted an extraordinary volume of informal consultations — bilateral meetings, small group discussions, and corridor conversations — to identify the real bottom lines of key delegations and to craft compromises that could command broad support. His ability to listen, to understand the domestic political constraints faced by different delegations, and to find formulations that allowed multiple parties to claim success was widely praised.

Fourth, he demonstrated a capacity for decisiveness when consensus proved impossible. When the United States, after completing its review, announced that it could not accept the Convention — primarily because of Part XI — Koh faced a stark choice: continue seeking a consensus that would never come, or put the Convention to a vote. He chose the latter, and on 30 April 1982, the Convention was adopted by 130 votes to 4, with 17 abstentions. The decision to vote was agonising — it represented a departure from the consensus principle that had governed the Conference for nine years — but Koh judged, correctly, that further delay would only erode support without producing agreement.

5.4 "A Constitution for the Oceans"

At the closing session in Montego Bay, Jamaica, on 6 and 11 December 1982, Koh delivered what became the most frequently cited statement in the history of the law of the sea. His remarks, titled "A Constitution for the Oceans," placed the Convention in its broadest context:

He described the Convention as "not merely a codification of existing rules" but "the establishment of a new legal order for the seas and oceans." He argued that it was "a monumental achievement of the international community, second only to the Charter of the United Nations." He characterised it as a comprehensive constitution, not merely a treaty — a framework that established the fundamental principles governing all human activities in the oceans and that could adapt to changing circumstances over time.

Koh was careful to note the Convention's imperfections. He acknowledged that no delegation had achieved everything it wanted, that the Convention represented a series of compromises, and that its true value lay in the totality of the package rather than in any individual provision. He expressed regret that the Convention had not been adopted by consensus, and he appealed to those states that had voted against or abstained to reconsider their positions.

The phrase "a constitution for the oceans" entered the vocabulary of international law and has been cited in virtually every significant academic treatment and legal argument concerning the Convention since 1982. It captured not just the Convention's scope but its aspiration — to provide a stable, comprehensive, and evolving legal framework for the two-thirds of the Earth's surface covered by water.

5.5 Singapore's Diplomatic Team and Its Strategy

Tommy Koh did not negotiate alone. Singapore's delegation to UNCLOS III included several officials who would themselves go on to distinguished careers. Most notable was S. Jayakumar (Shanmugam Jayakumar), a law professor at the University of Singapore who served as a member of Singapore's delegation and who would later become Singapore's Foreign Minister (1994-2004) and eventually Senior Minister and Coordinating Minister for National Security. Jayakumar co-authored with Koh the definitive account of the Conference's negotiating process, published in the Virginia Commentary on the Convention.

Singapore's negotiating strategy was sophisticated for a state of its size. On the straits issue, Singapore worked closely with the major maritime powers — the United States, the Soviet Union, the United Kingdom, France, and Japan — to ensure that the transit passage regime would be robust and unqualified. At the same time, Singapore had to manage its relationships with Malaysia and Indonesia, the other bordering states of the Straits of Malacca and Singapore, which had different — though not entirely opposed — interests. Malaysia and Indonesia wanted recognition of their sovereignty over the strait and the right to regulate navigation for environmental and safety purposes; they did not, however, want to close the strait to international shipping, which would have damaged their own trade.

On other issues, Singapore generally aligned with the Group of 77 developing countries. It supported the EEZ concept, the common heritage principle for the deep seabed, and the provisions on technology transfer and marine scientific research. This alignment with the developing world on the majority of issues gave Singapore's diplomats the credibility to serve as bridge-builders and honest brokers — a role that was essential to Koh's effectiveness as Conference President.

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6. Key Figures

Tommy Koh Thong Bee (born 1937) — President of UNCLOS III (1981-1982); Singapore's Permanent Representative to the United Nations (1968-1971, 1974-1984); Ambassador to the United States (1984-1990); Dean of the Faculty of Law, University of Singapore (1971-1974); subsequently Chairman of the National Arts Council, Ambassador-at-Large, and Special Adviser to the Institute of Policy Studies. The central figure in this narrative and arguably Singapore's most internationally recognised diplomat.

Hamilton Shirley Amerasinghe (1913-1980) — Sri Lankan diplomat who served as President of UNCLOS III from its inception in 1973 until his death in December 1980. Amerasinghe guided the Conference through its most formative years and established many of the procedural norms that Koh would inherit. His death created the vacancy that brought Koh to the presidency.

Arvid Pardo (1914-1999) — Malta's Ambassador to the United Nations, whose 1967 speech proposing the deep seabed as the "common heritage of mankind" set in motion the process that led to UNCLOS III. Often called the "father of the Law of the Sea Convention."

S. Jayakumar (Shanmugam Jayakumar) (born 1939) — Law professor, member of Singapore's UNCLOS delegation, subsequently Foreign Minister (1994-2004), Minister for Law, Deputy Prime Minister, and Senior Minister. Jayakumar's experience at UNCLOS III shaped his approach to international law and diplomacy throughout his subsequent career.

S. Rajaratnam (1915-2006) — Singapore's Foreign Minister (1965-1980) and subsequently Senior Minister. Rajaratnam set the strategic direction for Singapore's foreign policy — the emphasis on international law, multilateralism, and the rule-based order — that Koh operationalised at UNCLOS.

Elliot Richardson (1920-1999) — US Special Representative for the Law of the Sea Conference under Presidents Nixon, Ford, and Carter. Richardson was a strong advocate for US participation in the Convention and worked closely with Koh to seek compromises on the deep seabed issue. The Reagan administration's rejection of the Convention was a personal defeat for Richardson.

Alan Beesley (1929-2015) — Canadian diplomat who served as Chairman of the Drafting Committee of UNCLOS III and played a critical role in the Conference's procedural architecture.

Satya Nandan (1936-2020) — Fijian diplomat who served as Chairman of an informal group on the deep seabed issue and later became the first Secretary-General of the International Seabed Authority.

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7. Stories and Anecdotes

The Three-Hour Breakfast

Tommy Koh has recounted that during the final sessions of UNCLOS III, he would routinely begin his day with a working breakfast at 7:00 am and not leave the conference premises until past midnight. On one occasion, a breakfast meeting with the head of a key delegation lasted three hours because the delegate in question — whose identity Koh has diplomatically declined to reveal — insisted on explaining his country's position on every single article of the draft Convention before agreeing to discuss any compromises. Koh listened patiently. "In multilateral diplomacy," he later observed, "the ability to listen is more important than the ability to speak."

The Singapore Paradox

Several Conference participants noted the irony of a Singaporean presiding over negotiations about the world's oceans. Singapore is one of the smallest countries in the world by land area, with no significant natural maritime resources, no fishing fleet of consequence, and one of the shortest coastlines of any sovereign state. Yet it is one of the world's busiest ports and most trade-dependent economies. Koh himself turned this apparent weakness into a strength: Singapore's very smallness and lack of territorial ambition made its representative a credible neutral party. "No one suspects Singapore of wanting to carve up the ocean floor," Koh reportedly told a colleague. A small state with no axe to grind was precisely what was needed to broker agreement among giants.

The Midnight Call from Washington

In 1982, as the Conference approached its final vote, Koh received a late-night telephone call from a senior US State Department official urging him to delay the vote to give the Reagan administration more time to complete its review. Koh, who had already extended the timeline repeatedly to accommodate the US, politely but firmly declined. He told the caller that the Conference had waited long enough, that further delay would cause the developing countries to lose confidence in the process, and that the Convention would be put to a vote as scheduled. The decision to proceed required considerable nerve: the United States was Singapore's most important strategic partner and its largest trading partner, and defying Washington was not something Singapore did lightly. Koh later explained his reasoning: "If I had delayed the vote, I would have lost the confidence of 130 countries in order to please one. That would have been the end of the Conference."

The Handshake at Montego Bay

At the signing ceremony in Montego Bay on 10 December 1982, Koh personally witnessed the signing of the Convention by representatives of 119 states. He has described the moment as the proudest of his professional life. "For nine years," he recalled, "people said the Conference would fail. They said you could not get 160 countries to agree on anything. We proved them wrong."

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8. Arguments and Rhetoric

Koh's Argumentative Framework

Tommy Koh's rhetorical approach at UNCLOS III — and throughout his subsequent career — was characterised by several distinctive features:

The appeal to the common interest. Koh consistently argued that the Convention served the collective interest of the international community, not the narrow interest of any single state or group. "The seas belong to all of us," he said. "No state, however powerful, can govern the oceans alone. Either we manage them together, through law, or we lose them to chaos." This framing — multilateral law as the alternative to anarchy — was the intellectual foundation of his presidency.

The package deal logic. Koh was the Convention's most articulate defender of the package deal approach. He argued that the Convention had to be accepted or rejected as a whole — that cherry-picking the provisions one liked while rejecting those one disliked would destroy the balance of compromises on which the entire edifice rested. This argument was directed primarily at the United States, which wanted to accept the navigational provisions while rejecting the deep seabed regime.

The small state argument. Koh repeatedly made the case that the rule of law in international relations was disproportionately important for small states. "Large states can protect their interests by force," he argued. "Small states can only protect their interests through law." This was a quintessentially Singaporean argument — the same logic that informed Singapore's approach to international relations more broadly — and it resonated with many developing countries that shared Singapore's vulnerability.

The pragmatic idealism. Koh described himself as a "pragmatic idealist" — someone who believed in the possibility of a just international order but who understood that such an order could only be built through practical compromises rather than ideological purity. This self-description captures the tension at the heart of UNCLOS III: the Convention was simultaneously an exercise in high idealism (the common heritage of mankind, the peaceful settlement of disputes) and hard-nosed bargaining (maritime zones, mining royalties, technology transfer).

The Rajaratnam-Koh Doctrine

Koh's approach to international law was deeply influenced by S. Rajaratnam's vision of Singapore's place in the world. Rajaratnam argued that Singapore's survival depended on the existence of a rule-based international order in which small states were protected by law rather than exposed to the power politics of their larger neighbours. The Law of the Sea Convention was, for Singapore, the supreme example of this principle in action: a small state could not guarantee its own freedom of navigation through military power, but it could help build a legal regime that bound all states — including the great powers — to respect that freedom.

This doctrine — that international law is the small state's best weapon — has remained central to Singapore's foreign policy from Rajaratnam through Jayakumar and beyond. Tommy Koh's role at UNCLOS was the doctrine's most dramatic vindication.

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9. The Contested Record

Did Koh Truly Build Consensus, or Did He Simply Call a Vote?

The most significant criticism of Koh's handling of the Conference's endgame is that he abandoned the consensus principle by putting the Convention to a vote on 30 April 1982. The United States and its supporters argued that more time and flexibility might have produced a Convention that all major states could accept. By proceeding to a vote, Koh — in this view — sacrificed universality for speed, producing a Convention that the world's most powerful maritime state refused to join.

Koh's defenders — and Koh himself — have argued that the US position under Reagan was essentially non-negotiable: the administration's objections to Part XI reflected a fundamental ideological opposition to the concept of international management of deep seabed resources, not a set of specific concerns that could be addressed through textual amendments. Waiting indefinitely for the United States would have been futile, and it would have allowed the developing countries' coalition to fracture as the political moment passed.

The subsequent history supports Koh's judgment to a degree: the Convention eventually achieved near-universal participation only after the 1994 Implementation Agreement substantially modified Part XI in ways that addressed the core US (and Western) objections. But the United States has still not ratified the Convention as of 2026, despite the support of every administration since Clinton's and despite the uniform recommendation of the US military, the State Department, and the oil and gas industry. Whether this outcome vindicates Koh's decision to proceed without the US, or demonstrates that the decision came at a lasting cost, remains debated.

The Part XI Problem

The deep seabed mining regime established by the original Part XI of the Convention was, by almost universal retrospective acknowledgment, flawed. It created an unwieldy institutional structure, imposed burdensome financial obligations on mining companies, required mandatory technology transfer, established production limitations to protect land-based mineral producers, and gave the International Seabed Authority decision-making procedures that were unacceptable to Western industrialised states. The 1994 Implementation Agreement effectively rewrote the regime, removing the most objectionable provisions and creating a more market-friendly framework.

The question is whether these flaws were avoidable at the time. The Group of 77 insisted on a robust international regime for the deep seabed as the price for accepting the navigational provisions that the maritime powers wanted. The maritime powers could not get transit passage without giving the developing countries something substantial on the seabed. Koh and other Conference leaders judged that the package, however imperfect, was better than no Convention at all. History largely bore this out, though the imperfections of Part XI delayed the Convention's entry into force by over a decade.

Singapore's Alignment with Maritime Powers on Straits

Singapore's close alignment with the United States, the Soviet Union, and other maritime powers on the straits issue was noted — and sometimes criticised — by neighbouring states, particularly Malaysia and Indonesia. The two larger states bordering the Straits of Malacca had a more complex set of interests: they wanted the economic and environmental benefits of extended jurisdiction while also wanting to maintain international trade through the strait. Singapore's insistence on the strongest possible transit passage regime was seen by some in Kuala Lumpur and Jakarta as prioritising the interests of external maritime powers over regional solidarity.

This tension has never fully disappeared. Malaysia and Indonesia have periodically asserted greater regulatory authority over the strait, particularly on environmental grounds, and Singapore has pushed back. The UNCLOS framework has provided the legal basis for managing these disagreements, but the underlying tension between coastal state sovereignty and navigational freedom remains.

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10. Outcomes and Evidence

The Convention's Impact

The United Nations Convention on the Law of the Sea has been ratified or acceded to by 169 parties as of 2026, making it one of the most widely ratified treaties in history. Its provisions have been extensively cited by international courts and tribunals, and many of its key concepts — the twelve-mile territorial sea, the 200-mile EEZ, the continental shelf regime, transit passage through straits — are now regarded as reflecting customary international law, binding even on non-parties.

The Convention's institutional machinery is functioning: the International Seabed Authority operates from Kingston, Jamaica; the International Tribunal for the Law of the Sea sits in Hamburg, Germany; and the Commission on the Limits of the Continental Shelf has received and processed dozens of submissions from coastal states seeking to extend their continental shelves.

Impact on Singapore

For Singapore, the Convention's most direct impact has been in three areas:

Straits passage. The transit passage regime established by Part III has provided the legal foundation for Singapore's continued prosperity as a global port and trading hub. Ships of all nations pass through the Straits of Malacca and Singapore under the Convention's transit passage provisions, and Singapore has been able to resist attempts by neighbouring states to impose restrictions that would impede navigation. The Convention also provided the framework for the cooperative management of the straits through mechanisms such as the Cooperative Mechanism on Safety of Navigation and Environmental Protection in the Straits of Malacca and Singapore, established in 2007.

Maritime boundaries. The Convention provided the legal framework for Singapore's maritime boundary delimitation with Malaysia and Indonesia. Singapore's maritime zones are among the smallest in the world — constrained by the proximity of Malaysian and Indonesian territory — but the Convention's principles for delimitation have provided a basis for negotiation and, where necessary, adjudication. Singapore and Indonesia concluded a treaty on the delimitation of their territorial sea boundary in the western part of the Singapore Strait in 1973 (before UNCLOS was adopted) and have since concluded further agreements for other segments.

The Pedra Branca case. The sovereignty dispute between Singapore and Malaysia over Pedra Branca (Pulau Batu Puteh), Middle Rocks, and South Ledge was referred to the International Court of Justice in 2003 under a Special Agreement. The ICJ delivered its judgment in 2008, awarding Pedra Branca to Singapore, Middle Rocks to Malaysia, and leaving the sovereignty of South Ledge to be determined by the maritime boundary delimitation. While this was a sovereignty case rather than a law of the sea case strictly speaking, it was intimately connected to maritime jurisdiction — whoever controlled the features controlled the surrounding maritime zones. The legal infrastructure of UNCLOS, and the broader culture of peaceful dispute settlement that it promoted, facilitated the resolution of this long-running dispute.

South China Sea. The UNCLOS dispute settlement mechanism was invoked by the Philippines in 2013 in its arbitration against China concerning the South China Sea. The arbitral tribunal's 2016 award — which ruled that China's "nine-dash line" claim had no basis in international law and that none of the features China occupied in the Spratly Islands were entitled to an EEZ — was one of the most consequential applications of the Convention. China rejected the ruling, raising fundamental questions about the Convention's enforceability. Singapore, while not a party to the dispute, has consistently supported the rule of law and the binding nature of the arbitral award, in keeping with the Rajaratnam-Koh doctrine that the rule-based international order is the small state's best protection.

Koh's Subsequent Career

Tommy Koh's success at UNCLOS launched one of the most distinguished diplomatic careers in Singapore's history:

• Ambassador to the United States (1984-1990): Koh served as Singapore's ambassador in Washington during a critical period, building relationships with the Reagan and Bush administrations and strengthening the US-Singapore defence and economic relationship.
• Rio Earth Summit (1992): Koh chaired the Main Committee of the United Nations Conference on Environment and Development (the Rio Earth Summit), demonstrating that his UNCLOS skills were transferable to other domains of multilateral negotiation.
• Ambassador-at-Large: Koh has served as Singapore's Ambassador-at-Large since the 1990s, representing Singapore on a wide range of international issues.
• National Arts Council: Koh served as founding chairman of the National Arts Council, reflecting his lifelong advocacy for the arts, culture, and the quality of life — interests that have made him an unusual figure in Singapore's governance elite, which has traditionally prioritised economic and security concerns.
• Institute of Policy Studies: Koh has been associated with the Institute of Policy Studies as chairman of its board and as a prolific commentator on social and public policy issues in Singapore.
• Public intellectual: Through his columns in the Straits Times, his speeches, and his books — including The Tommy Koh Reader and The Quest for World Order — Koh has been one of Singapore's most visible public intellectuals, advocating for a more gracious society, greater support for the arts, and a more inclusive approach to social policy.

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11. What the Archive Has Not Yet Revealed

Several aspects of this history remain incompletely documented:

• The internal Singapore government deliberations on UNCLOS strategy are not publicly available. How were decisions made about Singapore's negotiating positions? What was the relationship between Koh in New York and the Ministry of Foreign Affairs in Singapore? How much latitude did Koh have to negotiate on his own authority, and how much did he need to refer back to Singapore? S. Jayakumar's memoir provides some insights, but the full picture remains classified.

• The diplomatic communications between Singapore and the United States during the critical 1981-1982 period, when Koh was simultaneously serving as Conference President and managing Singapore's bilateral relationship with Washington, would illuminate how Singapore balanced its role as an honest broker with its strategic interest in maintaining good relations with the United States.

• The role of Lee Kuan Yew in the UNCLOS process is not well documented. Lee was intensely interested in foreign policy and maritime security, and it is difficult to believe that he did not take a direct interest in the straits passage issue. But his memoirs contain relatively little on UNCLOS specifically, and Koh's own accounts focus on the multilateral process rather than domestic decision-making.

• The relationship between Koh and the Malaysian and Indonesian delegations during the straits negotiations deserves fuller treatment. How did Singapore manage the tension between its alliance with the maritime powers on transit passage and its need to maintain cooperative relations with its immediate neighbours? Were there private understandings or side deals that are not reflected in the public record?

• Koh's unpublished papers and correspondence, if they become available to researchers, would likely shed significant light on the informal diplomacy that was essential to the Conference's success. Multilateral negotiations of this kind leave a thin official record; the real story is in the letters, notes, and recollections of the participants.

• The full extent of the Singapore delegation's influence on specific provisions of the Convention — beyond the straits issue — is not well documented. Singapore's small size may have limited its ability to shape provisions on issues like the EEZ, continental shelf, and deep seabed mining, but the country's diplomats were active across all committees, and a detailed analysis of their contributions would enrich the record.

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12. Spiral Expansion Triggers / Spiral Index

This document generates the following requirements for additional corpus documents:

Level 2 Deep Dives

• SG-F-09: The Pedra Branca Case — sovereignty dispute with Malaysia, ICJ judgment 2008, application of maritime law principles
• SG-F-11: Singapore and the South China Sea — UNCLOS, the Philippines v. China arbitration, and Singapore's interests in freedom of navigation
• SG-F-12: The Straits of Malacca and Singapore — Strategic Waterway — historical, commercial, and legal significance; cooperative management mechanisms; piracy and security
• SG-F-13: Singapore's Maritime Boundary Delimitation — treaties with Indonesia and Malaysia, technical and legal issues

Level 3 Profiles

• SG-G-DIPLOMAT-01: Tommy Koh — full biographical profile covering UNCLOS, ambassadorship to the US, Rio Earth Summit, arts advocacy, public intellectual role
• SG-G-DIPLOMAT-02: S. Jayakumar — from UNCLOS delegate to Foreign Minister to Senior Minister; the lawyer-diplomat in Singapore's governance
• SG-G-DIPLOMAT-03: S. Rajaratnam — Foreign Minister, architect of Singapore's foreign policy doctrine (cross-reference with SG-H-DPM-02)

Level 4 Anthology Entries

• SG-ANTH-DIPLOMACY-01: Singapore's Greatest Diplomatic Speeches — to include Koh's "Constitution for the Oceans" closing statement
• SG-ANTH-SMALLSTATE-01: Arguments for the Rule-Based International Order — the Rajaratnam-Koh doctrine and its applications
• SG-ANTH-LEADERSHIP-01: Singaporeans Who Shaped International Institutions — Koh at UNCLOS, Jayakumar at ICJ, others

Institutional Documents

• SG-INST-MFA-01: Ministry of Foreign Affairs — institutional history, staffing, training of Singapore's diplomatic corps
• SG-INST-ITLOS-01: Singapore and the International Tribunal for the Law of the Sea — participation, cases, judges

Policy Consequence Documents

• SG-PC-STRAITS-01: Freedom of Navigation through the Straits of Malacca and Singapore, 1982-2025 — how the UNCLOS regime has operated in practice; challenges from piracy, environmental regulation, and coastal state assertions

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13. Sources and References

Primary Sources

1. United Nations Convention on the Law of the Sea, opened for signature 10 December 1982, 1833 UNTS 397 (entered into force 16 November 1994). The full text is available at the UN Division for Ocean Affairs and the Law of the Sea.

2. Tommy Koh, "A Constitution for the Oceans," remarks by the President of the Third United Nations Conference on the Law of the Sea, 6 and 11 December 1982. Reproduced in The Law of the Sea: Official Text of the United Nations Convention on the Law of the Sea with Annexes and Index (New York: United Nations, 1983).

3. Agreement Relating to the Implementation of Part XI of the United Nations Convention on the Law of the Sea of 10 December 1982, adopted 28 July 1994, 1836 UNTS 3.

4. Singapore Parliamentary Debates (Hansard), various sessions relating to maritime policy, the Law of the Sea, and the Straits of Malacca and Singapore.

5. International Court of Justice, Sovereignty over Pedra Branca/Pulau Batu Puteh, Middle Rocks and South Ledge (Malaysia/Singapore), Judgment of 23 May 2008, ICJ Reports 2008, p. 12.

6. Arbitral Tribunal constituted under Annex VII of UNCLOS, The South China Sea Arbitration (The Republic of Philippines v. The People's Republic of China), Award of 12 July 2016, PCA Case No. 2013-19.

Secondary Sources

1. Tommy Koh and Shanmugam Jayakumar, "The Negotiating Process of the Third United Nations Conference on the Law of the Sea," in Myron H. Nordquist (ed.), United Nations Convention on the Law of the Sea 1982: A Commentary, Vol. I (Dordrecht: Martinus Nijhoff, 1985).

2. Tommy Koh, The Quest for World Order: Perspectives of a Pragmatic Idealist, edited by Amitav Acharya (Singapore: Times Academic Press, 1998).

3. Tommy Koh, The Tommy Koh Reader: Favourite Essays and Lectures (Singapore: World Scientific, 2013).

4. S. Jayakumar, Diplomacy: A Singapore Experience (Singapore: Straits Times Press, 2011).

5. Lee Kuan Yew, From Third World to First: The Singapore Story 1965-2000 (Singapore: Times Editions, 2000), particularly chapters on foreign policy and Singapore's place in the world.

6. Robert Beckman, "The UN Convention on the Law of the Sea and the Maritime Disputes in the South China Sea," American Journal of International Law 107, no. 1 (2013).

7. James Harrison, Making the Law of the Sea: A Study in the Development of International Law (Cambridge: Cambridge University Press, 2011).

8. R.R. Churchill and A.V. Lowe, The Law of the Sea, 3rd ed. (Manchester: Manchester University Press, 1999).

9. Myron H. Nordquist, Satya N. Nandan, and Shabtai Rosenne (eds.), United Nations Convention on the Law of the Sea 1982: A Commentary, 7 vols. (Dordrecht: Martinus Nijhoff, 1985-2011) — the authoritative commentary, commonly known as the "Virginia Commentary."

10. Mark J. Valencia, Jon M. Van Dyke, and Noel A. Ludwig, Sharing the Resources of the South China Sea (The Hague: Martinus Nijhoff, 1997).

11. Ministry of Foreign Affairs, Singapore, Singapore's Foreign Policy: The First 50 Years (Singapore: World Scientific, 2016).

12. Chan Heng Chee, "Singapore's Foreign Policy, 1965-1968," Journal of Southeast Asian History 10, no. 1 (1969).

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This document is part of the Singapore Governance Knowledge Corpus. It should be read in conjunction with the related documents listed in the header block and the spiral index in Section 12.