📘 Overview of the Gulf of Tonkin Agreement

On 25 December 2000, China and Vietnam signed the Agreement on Delimitation of the Territorial Sea, Exclusive Economic Zone (EEZ), and Continental Shelf in the Gulf of Tonkin, alongside a Joint Fisheries Agreement. The agreements came into effect on 30 June 2004 after prolonged discussions over fisheries management.

Interestingly, only the Joint Fisheries Agreement is publicly accessible, while the full text of the EEZ delimitation agreement remains classified. However, through media and diplomatic sources, a rough outline of the agreement can be inferred.

📜 Main Components of the EEZ Agreement

Based on Chinese media (环球时报, Xinhua), the agreement consists of:

  • A preamble, 11 articles, and an annex

  • Articles 1–5: Define EEZ and continental shelf boundaries using 21 coordinate points

  • Articles 6 & 9: Cover legislative aspects of maritime law in each country

  • Article 8: Lays out common rules for resource protection, management, and exploitation

  • Article 10: Provides a dispute resolution mechanism

  • Article 11: Specifies the agreement’s entry into force

This structured format closely reflects UNCLOS principles, emphasizing both sovereign rights and peaceful cooperation.

🏝️ Jurisdiction of Islands: Bai Long Wei Dao Case

A central issue in the Gulf of Tonkin negotiations was the status of Bai Long Wei Dao (Bạch Long Vĩ Island). The agreement allowed the island:

  • 12 nautical miles of territorial sea

  • 3 nautical miles of EEZ and continental shelf

This represented a concession by China, as previous proposals excluded this island from having any EEZ entitlement. Chinese media noted on 1 July 2004 that Chinese fishing vessels were banned from operating within 15 nmi of the island, implicitly recognizing Vietnamese jurisdiction.

📐 Single Maritime Boundary: A Key Feature

A notable aspect of this agreement is the use of a single delimitation line for both the EEZ and the continental shelf. A Chinese maritime official described it as a “landmark compromise” that resolved dual-zone issues through one unified line.

“Although UNCLOS distinguishes between the EEZ (biological resources) and the continental shelf (mineral resources), in practice, these zones overlap. A single line ensures long-term efficiency and reduced conflict.”
— Chugoku Nambang News, August 2004

This precedent could inform future negotiations in other disputed maritime zones involving China.

🇰🇷 What This Means for Korea

South Korea can draw key lessons from the Gulf of Tonkin precedent as it prepares for future maritime boundary talks with China, especially in the:

  • Yellow Sea (West Sea)

  • East China Sea

Key takeaways include:

  • Flexibility in boundary approaches (equidistance vs. equity)

  • Recognition of partial EEZ rights for minor islands

  • Joint resource management as a compromise

  • Use of single-line delimitation to simplify negotiations

However, Korea must also factor in external variables, such as:

  • U.S. presence and influence

  • North Korea's strategic weight

  • Regional competition with Japan

These factors could either facilitate or complicate the negotiations, depending on political dynamics at the time.

🧭 Conclusion

The Gulf of Tonkin Agreement between China and Vietnam stands as a rare example of peaceful, negotiated maritime boundary delimitation involving China. It presents practical lessons and legal strategies that South Korea may consider in its future engagements with China on EEZ and continental shelf boundaries.