The government can revoke the Memorandum of Understanding (MoU 43) signed with Cambodia without a referendum due to serious breaches by the Cambodians, said Panthep Puapongpan, chairman of the Thailand Watch Foundation.
He said such a move could be justified under Section 60 of the 1969 Vienna Convention on the Law of Treaties, which permits unilateral termination in the event of a grave violation by one party. He cited recent violent incidents — including alleged Cambodian use of military weapons and explosive devices on Thai soil — as evidence of a grave treaty breach that legitimises immediate action.
Mr Panthep said he opposed the government’s proposal to hold a public vote on the issue, arguing that conducting a referendum alongside a general election would burden the next government and yield non-binding results.
“If the government insists on a referendum, I will campaign to repeal MoU 43 to protect Thailand’s sovereignty and compel Cambodia into fair, modern negotiations,” he said.
Mr Panthep said Thai borders were already defined in the reign of King Rama V using natural watershed lines such as cliff ridges from Chong Bok in Ubon Ratchathani to the Chong Sangam area in Si Sa Ket.
“Thailand and Cambodia coexisted for more than a century without MoUs, but since MoU 43, Cambodia has repeatedly encroached on Thai territory, relying on a 1:200,000 French colonial map that disadvantages Thailand,” he said.
He dismissed concerns that cancelling MoU 43 would allow Cambodia to take Thailand to the International Court of Justice, pointing out that Thailand had withdrawn from the ICJ in 1960. Instead, he proposed using existing mechanisms — the Thai-Cambodian Joint Boundary Commission, Regional Border Committee, and General Border Committee — for future negotiations.
Mr Panthep also rejected third-party mediation.