A one-page notice from Cambodia’s Geneva mission brought it into a temporary system for settling trade appeals on 3 September. The two countries it buys most from are inside. Its biggest customer, the United States, which took an estimated 40 per cent of its exports last year, is not.\
Cambodia joined a stopgap system for trade appeals on 3 September, with a one-page notice from its diplomatic mission to the World Trade Organization (WTO) in Geneva. The WTO, the global body whose rules govern trade between governments and which hears disputes between them, circulated the notice the next day. The European Commission welcomed the move in a statement on 9 September.
The system is the Multi-Party Interim Appeal Arbitration Arrangement (MPIA). Nineteen WTO members set it up in April 2020, and the notices the WTO has circulated since show 16 more joining, Cambodia the latest. That makes 35 participants, with the European Union counted once.
China, the EU, Vietnam, Japan, Canada, Britain, Singapore and Malaysia are in. The United States, Thailand, Indonesia and South Korea are not.
That line runs straight through Cambodia’s trade. The National Bank of Cambodia, the central bank, estimates from customs data that the country sold $31.3 billion of goods abroad in 2025. Its biggest customer was the United States, which took 40 per cent. Added together, the bank’s figures for countries inside the MPIA come to roughly half.
Imports run the other way. China supplied 56 per cent of the $36.2 billion Cambodia bought abroad, the bank says, and Vietnam 12 per cent. The three suppliers the bank names outside the MPIA provided 14 per cent between them: Thailand 9, Indonesia 3 and South Korea 2.
Why does an appeals stopgap exist at all? The WTO has a standing appeals court, the Appellate Body, and it is not working. A government that loses a trade case can still lodge an appeal. With no court to hear it, the case never reaches a binding end. The practice has a name: appealing into the void.
The MPIA gets around that, but only between its own participants. They say they will not appeal to the Appellate Body against one another. Instead, for each dispute between two of them, they say they will sign an agreement that sends any appeal to three arbitrators. These are independent trade-law experts drawn from a standing pool of ten. In that agreement both sides promise to abide by the arbitrators’ ruling, called an award, which is final. Either side can start the appeal, and governments outside the case cannot.
The arrangement is temporary. It lasts only until the Appellate Body works again, and a participant can withdraw.
Like the 15 members that joined before it, Cambodia came in by a notice to the WTO. Set side by side, its wording closely follows the notice Britain filed in June 2025. Both press for a wider reform of WTO dispute settlement, one that delivers “compulsory, binding, and impartial dispute settlement.”
Four WTO members had urged Cambodia to take the step. At its trade policy review in March 2025, a periodic WTO check on one member’s trade policies, Singapore, China, Australia and the Philippines, all MPIA participants, encouraged it to join. Cambodia replied that it was watching how the arrangement worked “very closely”. It spoke as the point person for the WTO’s least developed countries on dispute-settlement reform. At home, officials from several ministries met on 4 February this year to assess whether joining was feasible, according to the Trade Policy Advisory Board, a government advisory body.
The MPIA also cuts the other way, through trade remedies. These are the anti-dumping, anti-subsidy and safeguard duties that WTO rules let a government put on imports. A sub-decree signed in August 2024, under a 2017 law, set out how a National Committee on Trade Remedies works. The commerce minister chairs it. Its tasks include running such cases.
In March 2025 Cambodia told the WTO that the committee handled anti-dumping investigations. It had taken no anti-dumping action, it said, and would notify its investigation procedures. In February this year the commerce ministry ran a workshop on putting trade remedies into practice. It covered the country’s draft sub-decrees on them, the state news agency Agence Kampuchea Presse reported.
In its notice, Cambodia says it supports the MPIA’s aims. It also reaffirms its commitment to a working dispute system open to every WTO member. The MPIA itself reaches China and Vietnam, the two countries it buys most from. It does not reach the United States, its biggest customer, or Thailand, its third-biggest supplier. And it reaches back into Cambodia’s own trade policy. Suppose the committee puts duties on Chinese or Vietnamese goods and Beijing or Hanoi challenges them at the WTO. By joining, Cambodia has said it will not answer a ruling against it by appealing into the void. It has also said that in any such dispute it will sign an agreement sending appeals to the arbitrators, one that binds both sides to accept their award as final.
None of that comes into play until a dispute arises. In its own report for the 2025 review, Cambodia said it had never been involved in a WTO dispute as of the end of 2024, whether as complainant, respondent or third party. A third party is a member that joins another’s case because it has an interest in the outcome.