Defences and the Burden of Proof in International Law

The burden of proving a defence is said to be on the party invoking it. As trite as this proposition may sound, in international law it hides a far more complex litigation reality. Distinctions must be made both in terms of types of claims in defence, and types of burdens this may impose on the respondent. This chapter distinguishes six different claims in defence: (i) objections to jurisdiction, (ii) objections to admissibility, (iii) exemptions, (iv) absence of breach, (v) exceptions, and (vi) defences under secondary rules. For each of these six claims in defence, five types of burdens are identified: (i) burden of raising a claim in defence, (ii) burden of production of evidence, (iii) burden of persuasion, (iv) quantum of proof, and (v) standard of review. Although for some claims in defence some types of burden are on the defendant, this is certainly not the case for all.