Observers Urge Cambodian Leaders to Ratify the UN Convention on the Law of the Sea (UNCLOS) to Reclaim Sea and Island Territories

By Ly Bunsun
Decades of maritime violations have prompted calls for Cambodia to ratify the UNCLOS to protect its maritime territory and reclaim islands including Koh Tral and Koh Kut, which have been seized by neighboring countries. An experienced border expert from the CNRP, Mr. Um Sam An, posted on social media that Mr. Horinouchi recently spoke directly about Cambodia’s maritime territorial issues with neighboring countries. Mr. Horinouchi said Cambodia should ratify the United Nations Convention on the Law of the Sea (UNCLOS) 1982 to resolve the maritime and island issues of Cambodia, which is currently in disputes with Thailand and Vietnam.

He said he has been seeing a maritime dispute between Cambodia and Thailand, especially Koh Kut, etc., Horinouchi’s remarks were made at a ceremony at the Le Royal Hotel in Phnom Penh on March 18, 2025. He stated that Mr. Horinouchi is a judge of the International Tribunal for the Law of the Sea (ITLOS), who is the representative of the Japanese Embassy in Cambodia.

Um Sam An, said that if the Cambodian National Assembly gives the authority to approve the UNCLOSE, sign a treaty on this law, and then Cambodia will sue Thailand and Vietnam to the International Court of Justice, then Cambodia will win at least half of the islands from Thailand and overlapping maritime territory of 2,600 square kilometers from Thailand and winning Koh Tral and the Krak Ses archipelagos, maritime territory of 30,000 square kilometers, and maritime territory of 10,000 square kilometers from Vietnam.

This issue, he urged Hun Sen to ratify the UN Convention on the Law of the Sea (UNCLOS) to protect maritime territories and islands and to sue Thailand at the International Court of Justice over the case of Koh Kut and the overlapping maritime territories of more than 20,000 square kilometers.

He added that UNCLOS is an international agreement that establishes a legal framework for all activities involving maritime and island disputes, and that ratifying the convention gives Cambodia a clear legal basis to claim Koh Kut and the maritime domain is in dispute with Thailand and demands Koh Tral, the Krak Ses archipelagos, and 30,000 square kilometers of maritime domain from Vietnam. ”The 1982 the UN Convention on the Law of the Sea (UNCLOS) , so we can sue Thailand and Vietnam to the International Court of Justice and we can reclaim at least half of Koh Kut and the 26,000 square kilometers of overlapping area with Thailand, and we can also reclaim Koh Tral, reclaim Koh Krak Ses, and the 30,000 square kilometers of our maritime territory that Vietnam controls. And it can also claim another 10,000 square kilometers of historical waters jointly controlled with Vietnam if the government ratifies the 1982 Law of the Sea, UNCLOS.

President of the Royal Academy of Cambodia, Dr. Sok Touch, acknowledged that the law of the sea is indeed the basis for protecting the oceans, but that the current problems Cambodia can overcome. “That’s the law, but nevertheless, we have to strengthen our capabilities so that they won’t dare to touch us, and we can also withstand this situation. This is my thinking.”

Um Sam An said Cambodian leaders should be ashamed. Former Japanese Ambassador to Cambodia, Mr. Horinouchi, has presented important clues and evidence to protect and reclaim Cambodian territory. He said that if the Hun family leaders still do not wake up and still do not consider the integrity of the territory, that really reflects more clearly that the leaders of the Hun family are really betraying the will of the people, destroying the land, and serving foreign ambitions. ”It reflects that the Hun clan, both father and son, have no intention of protecting our maritime territory, our islands, under the invasion of Thailand and Vietnam, that means he wants to cede Koh Kut to Thailand so that Thailand can help protect its power, wants to cede our overlapping maritime territory of more than 26,000 square kilometers to Thailand. Another thing is that he agrees to cede Koh Tral, Koh Krak Ses, etc. “The historical waters belong to Vietnam because Hun Sen gave Koh Tral to Vietnam in 1982. So what is his intention to reclaim?”

Hun Sen has previously denied accusations that under his leadership, he has not lost territory to neighboring countries. “We cannot accept any accusations with what we have done for our national interests.” It’s going to be an Indochinese federation. It’s going to be something like the Indochinese Triangle. Some people call it the Golden Triangle. It’s too crazy. If you’re crazy, just go for it. Don’t make people crazy.
Cambodian observer Men Nat says that the 1982 the UN Convention on the Law of the Sea (UNCLOS) plays an important role in helping countries around the world that are currently in maritime disputes and meetings with neighboring countries. He said that in cases of maritime disputes between Vietnam and China, such as Lippincott and China, the 1982 UNCLOS is often used to resolve them and to prevent wars from happening. He believes that it is imperative for the Cambodian National Assembly and Cambodian leaders to ratify the 1982 Convention on the Law of the Sea to protect Cambodia’s maritime territory or archipelago. ”Cambodia needs to ratify the law of the sea, including relevant international laws to protect Cambodia’s territorial integrity. The first thing the government must do is to remember that if the government has a nationalistic view of the territory, but refuses to grant legitimacy, “they are still ignoring the people and just talking nonsense. No matter how much they lie, the next leaders, from Hun Sen to Hun Manet, will condemn the old government as a government of traitors. They really need to think about it.”

The Hun family government, which has been in power for decades, has been criticized for causing the loss of much territory to Vietnam, both mainland and archipelago, including the Koh Tral, as well as threatening the constitutional monarchy. If the King dares to oppose Vietnam’s territorial ambitions by making a clearly erroneous border treaty in 2005. However, according to Article 52 of the Constitution, the Royal Government of Cambodia is determined to preserve and protect the independence, sovereignty, and territorial integrity of Cambodia and implement a national unification policy for national unity. Specifically, according to Article 450 of the Penal Code, anyone who causes the loss of all or part of the territory is considered an act of treason and is subject to life imprisonment.

Jacques Perlet, French Ambassador to Cambodia, has called on Cambodia to ratify the United Nations Convention on the Law of the Sea (UNCLOS) to facilitate the resolution of maritime border and islands issues with Vietnam and Thailand, especially Koh Kut. He said on May 5th at the French Embassy that he had not yet received detailed information about the border issue between Cambodia and neighboring countries.

An International Judge Horinouchi also told Cambodia to ratify the 1982 United Nations Convention on the Law of the Sea (UNCLOS) to gain maritime benefits and resolve Cambodia’s disputed maritime and island territories with Thailand and Vietnam. His proposal, given that there is a dispute over the overlapping maritime boundary between Cambodia and Thailand, especially Koh Kut, was made by Judge Horinouchi Hidehisa, a judge of the International Tribunal for the Law of the Sea (ITLOS) and a former Japanese ambassador to Cambodia.

Although Cambodia signed the United Nations Convention on the Law of the Sea (UNCLOS) in 1983, it is not yet complete and requires further ratification of the UNCLOS to be complete.

The French President once said that he was ready to help Cambodia resolve its border issues if requested by Cambodia, and international judge Horinouchi also told Cambodia to ratify the United Nations Convention on the Law of the Sea (UNCLOS).

And now, Jacques Perret, the French ambassador to Cambodia, has asked Cambodia to ratify the UNCLOS.

Does Cambodia want to protect its maritime and island territories or not?

Please note that France was the one who drew the map and defined the borders of Cambodia, neighboring country, during the French colonial era.
Um Sam An stated on his Facebook page that it is suspected that Hun Sen, who has led the country for more than 40 years, has refused to ratify the UNCLOS because the UNCLOS will affect the 1982 Treaty on the Historical Water Zone, signed by Hun Sen during the Vietnamese rule of Cambodia, and the application of the United Nations Convention on the Law of the Sea (UNCLOS) will affect the Cambodian islands of Tral and Krak Ses, which Vietnam is occupying, especially if Cambodia sues Vietnam in an international court using the Law of the Sea (UNCLOS). He added that, however, we request that Mr. Hun Manet ratify the Law of the Sea (UNCLOS) to protect maritime and island territories and sue Thailand to the International Court of Justice over the Koh Kut case and the 26,000 square kilometer overlapping maritime territory.
Note: United Nations Convention on the Law of the Sea (UNCLOS)