21/12/2025
Open Letter and the United Nations, ASEAN, and the International Community to be heard.
Condemnation of Thailandâs Armed Aggression Against the Kingdom of Cambodia
Since 7 December 2025, the Kingdom of Cambodia has been subjected to deliberate, systematic, and large-scale armed aggression by the armed forces of the Kingdom of Thailand along Cambodiaâs western border. These actions are neither accidental nor defensive, nor can they be characterized as spontaneous border incidents. They constitute a premeditated and coordinated military campaign, publicly ordered, executed, and acknowledged by Thai state authorities.
Thailand has deployed land, air, and naval forces simultaneously, conducting incursions deep into Cambodian territory and planting its flag on Cambodian soil. These operations represent a flagrant violation of Cambodiaâs sovereignty, territorial integrity, and political independence, in direct contravention of the United Nations Charter, the ASEAN Charter, and fundamental principles of international law.
I. Cambodia Is Not, and Cannot Be, the Aggressor
Cambodia is a small nation in terms of territory, military capability, and strategic posture. It lacks both the capacity and the intent to initiate hostilities against a neighboring state with vastly superior military power. Any assertion to the contrary is factually implausible and legally unsustainable.
Cambodia has consistently exercised maximum restraint and has repeatedly called for peaceful settlement of disputes through dialogue and legal mechanisms. This includes Cambodiaâs acceptance of the ceasefire of 28 July 2025 and the Joint Declaration for Peace of 26 October 2025. Since 1998, Cambodia has devoted its national resources to reconstruction, reconciliation, and peacebuilding following decades of devastating conflict. A state so deeply committed to peace has no rational motive to instigate war.
II. International Law Unequivocally Supports Cambodiaâs Position
Cambodiaâs borders are founded on internationally recognized treaties and legal instruments, including the Franco-Siamese Treaties of 1904 and 1907 and the Memorandum of Understanding of 2000. These instruments remain valid under international law and have long been acknowledged by the international community.
Thailandâs reliance on unilateral and self-produced mapsâlacking international recognitionâcannot justify territorial claims or the use of force. Under international law, no state may alter borders through military means, nor invoke disputed interpretations to legitimize armed aggression.
III. Cambodia Has Chosen Law; Thailand Has Chosen Force
Cambodia has consistently pursued legal and judicial avenues to resolve border disputes. The International Court of Justice ruled decisively in 1962 and reaffirmed in 2013 that sovereignty over Preah Vihear and its surrounding areas belongs to Cambodia.
In light of these rulings, Cambodia has every legal incentive to uphold international law and no incentive whatsoever to abandon it in favor of war. Thailandâs resort to weapons instead of law represents a clear rejection of judicial settlement and a dangerous contempt for the international legal order.
IV. Cambodia Knows the Cost of War and Rejects It
Having suffered two wars and a genocide between 1970 and 1998, Cambodia understands, more than most nations, the catastrophic human cost of armed conflict. Peace, stability, and socio-economic development are therefore Cambodiaâs highest national priorities.
This commitment has been recognized internationally through multiple peace-related honors in recent years. Cambodia has no interest in destroying the hard-won peace achieved through decades of sacrifice. The suggestion that Cambodia would willingly return to war is both morally offensive and historically absurd.
V. Thailand Has Initiated and Waged This War
Since 7 December 2025, Thai authorities have openly ordered and conducted large-scale military operations along more than 800 kilometers of the Cambodian border, with reported incursions reaching 80â90 kilometers inside Cambodian territory.
These operations have involved F-16 and Gripen fighter jets, cluster munitions, armed drones, heavy artillery, long-range rockets, tanks, and armored vehicles, supported by coordinated land, air, and naval forces. These attacks have not been confined to military objectives. They have struck civilians, homes, schools, pagodas, roads, refugee camps, and Khmer temples and historical monuments, including sites recognized as World Heritage.
Such acts cannot be justified under Article 51 of the UN Charter as self-defence. They constitute a grave breach of international law, a manifest act of armed aggression, and potential war crimes, for which Thailand bears full responsibility.
Appeal to the United Nations, ASEAN, and the World
Cambodia formally calls upon:
⢠The United Nations to condemn Thailandâs armed aggression, to take urgent measures to protect civilians, and to uphold the UN Charterâs prohibition on the use of force.
⢠ASEAN to act in accordance with its Charter and founding principles, including peaceful dispute resolution and respect for sovereignty, and to reject the normalization of military coercion within the region.
⢠The international community to refuse silence, neutrality, or ambiguity in the face of clear violations of international law.
Failure to act decisively would embolden further aggression, undermine regional stability, and erode the credibility of the international system founded on the rule of law. This is not solely a matter concerning Cambodia. It is a test of whether law or force will govern relations between states in the 21st century.
The Kingdom of Cambodia seeks justice, accountability, and peaceânot through weapons, but through the firm and principled application of international law.
