Letter of Condemnation on Thai Aggression Against Cambodian Territory
As a senior fellow, board member and former Executive Director of the Cambodian Institute for Cooperation and Peace, I wish to express my grave concern and strongly condemn the ongoing military aggression by the Kingdom of Thailand against the sovereign territory of the Kingdom of Cambodia.
I wish to highlight the following:
1. Historical Context: Cambodia and Thailand share a long and complex history of territorial disputes. Cambodia has consistently based its claims on internationally recognized maps, particularly those stemming from the 1907 Franco-Siam Treaty, which was acknowledged by the United Nations and the International Court of Justice (ICJ). In contrast, Thailand has relied on unilaterally drawn military maps created decades later. These conflicting interpretations have led to multiple armed-clashes and legal confrontations, including cases brought before the ICJ.
2. Escalation of Armed Conflict: What began as localized border clashes has now escalated into a full-scale invasion by a militarily superior state against a smaller, less equipped neighbor. This aggression constitutes a clear violation of the ASEAN Treaty of Amity and Cooperation, undermining the principles of peaceful coexistence and mutual respect. The conflict has resulted in the tragic loss of both combatant and civilian lives and has displaced hundreds of thousands of innocent people.
3. Humanitarian Crisis and Disproportionate Force: While both sides have employed heavy artillery, the Thai military has reportedly deployed a full spectrum of warfare—including ground forces, tanks, cluster munitions, toxic gas, fighter jets, and naval units—against Cambodian territory. These actions have devastated civilian infrastructure, including homes, schools, pagodas, roads, bridges, and ancient temples. Entire communities along the border have been forced to flee, abandoning their homes, crops, and livestock. The scale of destruction and human suffering is both unacceptable and heartbreaking.
Therefore, I, solemnly:
1. Condemn the ongoing military aggression by the Thai armed forces and call for an immediate cessation of all hostilities, including aerial bombardments, artillery shelling, and other forms of violence and suppression.
2. Reaffirm that Cambodia, as a small and peaceful nation, harbors no ambition to invade or threaten the sovereignty of Thailand.
3. Urge both governments to resolve their border disputes through peaceful dialogue, in accordance with international law, the ICJ rulings, and relevant treaties, with patience, mutual respect, and trust.
4. Appeal to ASEAN, the United Nations, and the international community—including major powers such as the United States, China, France, and the United Kingdom—to
take urgent and impartial action to broker an unconditional ceasefire and facilitate a durable peace.
I stand in solidarity with all victims of this conflict and call for a return to diplomacy, justice, and regional harmony.
Phnom Penh, Cambodia
26 December 2025
Chap Sotharith, Ph.D
Senior Fellow, Board Member and Former Executive Director
Cambodian Institute for Cooperation and Peace (CICP)