Viewpoint: Thailand's Invasion of Cambodia and Violations of International Laws?

Thailand's Invasion of Cambodia: Violations of International Laws?

Cambodia and Thailand flags by Depositphotos through the Diplomat

Cambodia and Thailand share a long border of approximately 885 km according to Sovereign Limits. Cambodia is a main country and a golden state in Southeast Asia, while Thailand is also based in Southeast Asia. Both countries are members of the Association of Southeast Asian Nations (ASEAN) and the United Nations. These two nations are a potential block for the power countries such as China and the U.S.; even in the past, France and England influenced these countries.

Along the country's border, in the past century, the Siamese often invaded Cambodia’s territory. Since French colonization, they have made a treaty between France and Siam on 23 March 1907. The French urged the Siamese to return Battambang and Angkor to Cambodia because the territory belonged to the ancient Khmer Empire. However, the Siam are not happy with this decision, even though it has been Khmer territory for many centuries. 

The border between Cambodia and Thailand has been the site of clashes many times in 1964, 2008, 2011, and 2025. The current border conflict now belongs to Cambodia based on the Franco-Siamese treaty since 1907. But Thailand, through the army, does not accept it.

Here are some hidden views and untold stories regarding border disputes: Thailand invaded Cambodia’s territory.

On 28 May 2025, Thai troops went into Cambodian territory and killed a Cambodian soldier who was in Cambodian territory. This violation of Cambodian territorial integrity is a violation of the Franco-Siamese Convention of 1904 and the Franco-Siamese Treaty of 1907.

The Thai troops invaded Cambodia, and attacked the Preah Vihear Temple and the Cambodian pagoda is the most serious violation of Cambodian sovereignty and a violation of the World Heritage Site, which UNESCO has registered as the Preah Vihear Temple since 7 July 2008.

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The Thai army used cluster bombs dropped from F-16 aircraft, and the firing of missiles is an extreme violation of the United Nations Convention on Cluster Munitions (CCM) on Cambodian territory several times since 24-27 July 2025. While the convention prohibits, under any circumstances, the use, development, production, acquisition, stockpiling, and transfer of cluster munitions, as well as the assistance or encouragement of anyone to engage in prohibited activities.

According to Kiri Post news, Thailand's targeted attacks on Cambodian civilians, pagodas, temples, and villages in Cambodia are grave violations of the humanitarian law of the United Nations Framework, which prohibits attacks on civilians, temples, and villages. In fact, during the conflict between 24 to 28 July 2025, many ordinary Cambodian houses, pagodas, and schools were bombed by using airstrikes.

Thailand’s use of force in defiance of the peaceful resolution of disputes and the involvement of the regional and international community is a flagrant violation of the ASEAN Charter, Article 2, which requires respect for the sovereignty of other member states of the ASEAN and the peaceful resolution of disputes, and a grave violation of Article 2(4) of the United Nations Charter. 

In summary points, Thailand’s invasion of Cambodian territory is not a recent occurrence; it has been going on for centuries, especially since the Khmer Empire. As an argument, in ancient times, all leaders of Siam, or Thailand, always attempted to invade and violate the legitimate territory of the Kingdom of Cambodia. 

However, through this writing, we hope that the Thai side will respect and dare to accept the use of ASEAN and international mechanisms so that the two countries can have a solution and long-term peace. In addition to the mediation of Malaysia, the United States, and China, France must also contribute to the mediation and encourage both parties to use international mechanisms following the treaties that France led in 1904-1907, in conjunction with the ASEAN mechanism and international law.

As both countries practice Buddhism and Christianity formally, we strongly condemn Thailand’s destruction of religious sites, which is prohibited by United Nations humanitarian law. As Cambodian citizens, we strongly condemn Thailand’s aggression against the sovereignty and territorial integrity of Cambodia. 

And Cambodian youths, we strongly condemn Thailand's aggression, which indiscriminately attacks civilians, homes, villages, and local people, who are innocent Cambodian citizens. We knew that innocent people from both countries did not want the war but wanted peace in the long term.

Through the knowledge and skills we have learned about international laws from schools, we would like to share some viewpoints that show the aspects that cause war and conflict along the Cambodian-Thai border. If there are any errors, please help correct us and provide suggestions with your knowledge and strong arguments.

Written by: Thy Thuch

Edited by: Blen Romam