The
issue of the law applicable to the res
judicata principle
in international arbitration carries an important practical weight given the
discrepancies, found in comparative law, surrounding the res judicata principle
itself. Yet, if the question is important, its answer appears, for several
reasons, rather difficult to find. Firstly, the doubts surrounding the notion
of res judicata itself
are not making the task at hand easy. Secondly, the issue of res judicata in
arbitration is, in fact, a topic that can be approached from different angles
since it may concern different decisions (arbitral awards, domestic courts’
decisions on the merits of a dispute, domestic courts’ decisions on arbitral
proceedings) and different authorities (arbitrators, domestic judges hearing
the merits of the dispute, the supporting judge (“juge d’appui” the judge
controlling the award). This article is however limited to the issue of the law
applicable to the res
judicata principle
from the arbitrator’s point of view, when the latter faces an award or a judgment
on the merits rendered in another proceedings whose res judicata is
invoked before him. Regarding this issue, the “conflictualist approach” is not
the most helpful. On top of the “usual” difficulties faced in private
international law when determining the law applicable to the res judicata principle—which
are already important when assessing the res judicata of
a court’s decision in another domestic proceedings, and are reaching even more
complexity in arbitration — we can add the relatively disappointing content of
the law eventually elected to deal with the issues triggered by the res
judicata principle in the specific context of international arbitration. However,
the substantive rules method (“méthode des règles matérielles”) which could
appear more appropriate, given the advantages supposedly granted to it by many
scholars, is also disappointing, at least given the current state of law. In
the end, a lot needs to be done in order to make things clearer. Notwithstanding
the latter, a few proposals can be made in that respect.