Res judicata vid internationellt skiljeförfarande

Sammanfattning: The overall purpose of this essay is to discuss how unpredictability in the application of res judicata in international arbitration can be eliminated. In most legal traditions res judicata constitutes a fundamental judicial norm with the meaning that a matter adjudged can not be tried again. A dispute identical to a previous dispute will hence be rejected with reference to res judicata. Differences in the application of res judicata arise when there are similarities between a current and a previous dispute, without them being identical. There are large differences between common law tradition and civil law tradition in the application and scope of res judicata in national courts. The application is in general wider in the common law tradition than in civil law tradition. As an example, in common law tradition res judicata also includes, besides the conclusion, the reasoning of a judgement. The consequence of the variation in res judicata’s content between different legal traditions is that there is no uniform approach with regards to how one should handle res judicata in international arbitration. Because of this, arbitral tribunals need to individually decide how to apply res judicata. Therefore, different arbitral tribunals tend to apply res judicata differently. The essay concludes that res judicata constitutes international customary law in international arbitration. The precise content of res judicata, however, does not follow from customary law, arbitration rules, conventions or other soft law. Arbitral tribunals influenced by civil law tradition will often consider res judicata to be a procedural rule and apply the view on res judicata in accordance with lex arbitri (the law of the seat of the arbitration). Arbitral tribunals influenced by common law tradition will on the other hand often consider res judicata to be a substantive rule and apply the view on res judicata in accordance with lex causae (the law of the contract). Other arbitral tribunals disregard the choice of law principles and instead freely interpret the content of res judicata. The lack of international norms clarifying the specific content of res judicata obstructs the parties’ possibility to predict whether res judicata will prohibit the dispute at hand. Confusions include who is considered to be a party, whether issue estoppel is applicable and at which moment in time res judicata can be applied. Unpredictability in res judicata’s content risks to cause harm to arbitration at large because the arbitral tribunal’s assessment appears to be arbitrary. The essay discusses different ways of harmonization of res judicata’s content in international arbitration and suggests a solution where the content does not need to be harmonized but rather the classification of res judicata as either a procedural or substantial rule. Such a solution increases the parties’ ability to predict the outcome of the res judicata assessment. At the same time this solution provides the parties with the opportunity to, by choosing lex arbitri and lex causae in their arbitration clause, decide which view on res judicata they prefer. Complete harmonization of res judicata’s content in international arbitration does not appear to be necessary in order to reduce the unpredictability. There is however no fully appropriate way to incorporate res judicata as either a procedural or a substantial rule in international arbitration. A first step towards harmonization of res judicata’s classification can however be to incorporate a harmonized classification of res judicata in arbitration rules such as the ICC Rules of Arbitration, LCIA Arbitration Rules, SCC Arbitration Rules and UNCITRAL Arbitration Rules.