State Succession and Devolution Agreements Revisited: A Note on Sanum v. Laos

In a recent judgment, the Singapore Court of Appeal quashed a prior judgment of the Singapore High Court, which had decided to set aside an arbitration award on the basis that the China–Laos bilateral investment treaty (bit) does not apply to Macao. The judgment of the Court of Appeal is significant inasmuch as it involves a thorough examination of the international law principles governing the law of State succession in respect of part of territory, the relative effect of treaties in the context of devolution agreements, and the relationship between the critical date rule (or intertemporal principle) and the interpretive norm of subsequent agreement or practice. Above all, the dialogue between the Singaporean courts and the arbitral tribunal (whose award was sought to be set aside) raise a number of interesting issues in respect of the territorial application of investment treaties in general and Chinese investment treaties in particular. It also bears noting that this dialogue and its impact on future cases has to be filtered through subsequent developments, most notably a statement issued by China’s Ministry of Foreign Affairs to the effect that the Court of Appeal judgment was incorrect.