The Court of Appeal affirmed the decision of the High Court (UK 127) that the principle of issue estoppel applies to the determination by an English court whether one of the exceptions to state immunity in the State Immunity Act 1978 applies – specifically here, when a foreign (Dutch) court has decided that a state has agreed in writing to submit a dispute to arbitration. The Court held that the State Immunity Act 1978 sets out c the exceptions to state immunity, but does not prescribe how the court should decide whether any of the exceptions applies in any given case. That question must be decided applying the ordinary principles of English law, both substantive and procedural, and those principles include the principle of issue estoppel.