The Incapacity Defence under art. V(1)(a) of the New York Convention

Under art. V(1)(a) of the New York Convention, an award may be refused recognition and enforcement if “[t]he parties to the agreement referred to in article II were, under the law applicable to them, under some incapacity”. The provision at stake raises a number of questions with regard to its meaning, scope and functioning. By taking into consideration the legislative history of the incapacity defence and the interpretative rules of the Vienna Convention of the Law of Treaties, this paper aims at sheding light on issues that are often overlooked in case law. On the one hand, it argues that reference to the personal law of the parties should be construed as requiring courts to fall back to their choice-of-law system in order to supplement the incomplete conflict of laws rule provided by the uniform regime. On the other hand it suggests that, at the stage of characterization, the concept of capacity should be interpreted restrictively.