The first of the Convention’s five respondent-proven grounds goes to the foundation: was a party incapable, or was the arbitration agreement invalid? Before the ADGM Courts, the answer turns on the right governing law — and on a high bar.
Two limbs
Article V(1)(a) lets a respondent resist enforcement on two related bases: that a party to the arbitration agreement was under some incapacity, or that the agreement was not valid. Both go to consent — the bedrock of arbitration — and both must be proved by the party resisting, not assumed by the court.
Which law governs validity
The Convention supplies its own conflict rule for the agreement's validity: the law to which the parties subjected the agreement, or, failing any indication, the law of the country where the award was made (the seat). This matters in practice. A respondent cannot simply argue that the clause would be invalid under some convenient third law; the ADGM Courts will apply the law the parties chose, or the law of the seat, and test validity there.
Consent is the bedrock — but the respondent must prove its absence, and against the law the parties chose or the law of the seat.
Incapacity
Incapacity is assessed under the law applicable to the party in question and is narrowly construed. Ordinary questions of corporate authority, agency or the power of a signatory are rarely enough; the ground addresses a genuine want of legal capacity to contract, not a belated complaint about internal approvals.
A high bar, and a common trap
Because Article V grounds are exhaustive and narrowly interpreted, a validity challenge that could have been raised before the tribunal — and was not — will struggle at the enforcement stage. Separability also confines the enquiry: an attack on the underlying contract is not, without more, an attack on the arbitration agreement. The disciplined respondent identifies a real defect in consent governed by the correct law; the disciplined creditor anticipates it long before the award is rendered.
Key instruments: New York Convention 1958 (Article V(1)(a)); UNCITRAL Model Law; ADGM Arbitration Regulations 2015. General information, not legal advice.