Cambodia Warns Thailand Against Scrapping Border Pact, Citing International Law

PHNOM PENH, Mar. 26, 2026 (KPT) — Cambodia has warned that cancelling a long standing border agreement with Thailand would breach international law and jeopardize efforts to resolve territorial disputes peacefully.

Government spokesman Pen Bona said Thursday that revoking the 2000 memorandum of understanding (MOU) would violate the principle of uti possidetis juris, which protects the inviolability of existing borders.

“Such a step would create obstacles to resolving disputes and undermine efforts to establish stable, peaceful and development oriented borders,” he said.

His comments followed Thai media reports that a Senate committee in Bangkok had proposed scrapping the pact, also known as MOU 43.

Cambodia’s Secretariat of Border Affairs rejected the proposal as baseless and politically motivated, warning it risked undermining progress made through the Joint Boundary Commission (JBC).

Officials stressed the MOU is a legally binding treaty registered with the United Nations, giving the JBC authority to address border issues based on historical treaties and maps.

Cambodia argued Thailand cannot invoke domestic law to terminate the agreement under the Vienna Convention on Treaties.

Bona said Cambodia remains committed to peaceful settlement, noting the JBC has already identified 74 colonial era markers, repaired posts, installed temporary markers and developed a joint geodetic network.