The sacrifice of Vietnamese officers and soldiers at Gac Ma in 1988, along with the relentless efforts of the nation’s military and civilians, has shaped today’s Vietnam. The country now stands confident as it prepares to chair the United Nations Convention on the Law of the Sea (UNCLOS) member states’ meeting in June 2025.

Editor’s note:

In early March 1988, the Chinese Navy mobilized a large force from its South Sea and East Sea Fleets to Truong Sa Archipelago of Vietnam in an attempt to seize control of three strategic reefs: Gac Ma, Co Lin, and Len Dao.

On March 14, 1988, while Vietnamese naval transport ships and soldiers were protecting Co Lin, Gac Ma, and Len Dao, Chinese warships opened fire, heavily shelling Vietnam’s HQ-604 at Gac Ma, HQ-605 at Len Dao, and HQ-505 at Co Lin.

At Gac Ma, Vietnamese officers and soldiers formed the "immortal circle" - holding hands to protect the national flag - determined to defend the island. Sixty-four Vietnamese Navy soldiers lost their lives in this battle, sacrificing themselves to protect the sovereignty of Truong Sa (Spratly Islands).

Thirty-seven years have passed, but the sacrifice of these 64 naval heroes and the loss of Vietnam’s three transport ships remain etched in national memory. Their courage contributed to shaping a Vietnam that is now a recognized force in international maritime law.

Ambassador Nguyen Hong Thao, Vietnam’s representative on the United Nations International Law Commission (ILC) for the 2023-2027 term, is a distinguished diplomat and legal expert. He has participated in critical border negotiations with China, Laos, and Cambodia. Before his diplomatic career, he was also a member of the 125th Naval Brigade, the same unit that fought in Gac Ma 1988.

Below is his exclusive article for VietNamNet.

From Gac Ma to chairing the UNCLOS member states’ meeting

Every March 14, the nation remembers the sacrifice of the soldiers from the Truong Sa 125 Naval Transport Brigade, the 126 Special Forces Brigade, the 83rd and 131st Naval Engineer Brigades, and many others who participated in the CQ-88 campaign. These heroes formed the immortal circle to protect Vietnam’s sovereignty.

Their sacrifice was not in vain. It contributed to defining Vietnam as a maritime nation, where three parts of its territory are sea and one part is land. This struggle also paved the way for Vietnam’s strong legal and diplomatic stance in UNCLOS 1982, enabling peaceful maritime dispute resolution.

At the end of February 2025, Vietnam received recognition in New York as the Asia-Pacific group at the UN unanimously nominated Vietnam to chair the 35th session of the UNCLOS member states’ conference (SPLOS), set to take place from June 23-27, 2025.

This recognition underscores Vietnam’s growing global reputation in upholding and promoting UNCLOS 1982, the most effective legal framework for resolving maritime disputes worldwide - including in the East Sea.

Defending maritime rights and interests

From Gac Ma to SPLOS 2025, Vietnam has steadfastly defended its independence while fostering diplomatic engagement with all nations. The strategic choices made in 1988, combined with Vietnam’s measured military response and diplomatic persistence, have been instrumental in securing Vietnam’s legal claims and establishing maritime boundaries.

After securing control of 21 features in the Spratlys, Vietnam faced a critical legal challenge - whether to integrate the DK1 platforms into the Spratly Islands or define them as part of Vietnam’s extended continental shelf.

Inspired by the sacrifice at Gac Ma, Vietnam took bold legal steps, ratifying UNCLOS 1982 in 1994 before the treaty even took effect. This decision enabled Vietnam to legally extend its maritime jurisdiction and establish a 200-nautical-mile exclusive economic zone (EEZ), as outlined in Vietnam’s 1977 Declaration on the EEZ and Continental Shelf - a landmark legal move in Southeast Asia.

Establishing Vietnam’s maritime legal framework

By February 2025, Vietnam had fully declared its baseline system, extending from Point 0 at the Vietnam-Cambodia historic waters boundary to Point A24 at the Vietnam-China Gulf of Tonkin boundary. This system employs both straight and normal baselines, aligning with UNCLOS regulations.

This legal framework sets the stage for defining baselines around the Hoang Sa (Paracel) and Spratly Islands in the future. With clear maritime boundaries, Vietnam can effectively manage its waters and strengthen law enforcement in the region.

Vietnam is also among the few East Sea nations that have fully submitted extended continental shelf claims. In 2009, Vietnam and Malaysia jointly submitted a continental shelf claim to the Commission on the Limits of the Continental Shelf (CLCS). Vietnam also submitted separate claims for the northern and central East Sea in 2009 and 2014.

By applying UNCLOS in maritime dispute resolution, Vietnam has helped validate and clarify key provisions of the convention.

Vietnam has pioneered the principle of equity in maritime delimitation, being the first nation to sign a dual boundary agreement with Indonesia, differentiating EEZ and continental shelf boundaries in overlapping maritime zones.

Additionally, Vietnam has led in provisional maritime agreements, implementing the Vietnam-Malaysia Joint Petroleum Development Area in the Gulf of Thailand (1995) - a global model for joint offshore resource development.

Vietnam also pioneered joint fishing agreements, such as the Vietnam-China Gulf of Tonkin fisheries agreement (2004), which remained valid until 2020.

Commitment to peaceful dispute resolution

Vietnam has consistently advocated for peaceful maritime dispute resolution, playing a key role in the Declaration on the Conduct of Parties in the East Sea Sea (DOC) and negotiations for the Code of Conduct (COC).

Vietnam was also a founding member of the Group of Friends of UNCLOS, reinforcing its commitment to international maritime law.

Domestically, Vietnam has enacted progressive maritime laws, including the 2012 Law of the Sea and the 2018 Law on the Coast Guard, ensuring legal compliance with UNCLOS.

Vietnam has always upheld UNCLOS principles in maritime governance, environmental protection, and peaceful dispute resolution, demonstrating the treaty’s essential role in securing fair and sustainable ocean management.

The sacrifice at Gac Ma and the tireless efforts of Vietnam’s diplomats and military have shaped today’s maritime Vietnam. As Vietnam prepares to chair the UNCLOS member states’ conference in 2025, it stands firm in helping nations establish a fair, lawful, and peaceful maritime order.

Nguyen Hong Thao