I regret that I cannot join my colleagues in that part of our decision which rejects jurisdiction over counterclaims “arising directly out of the subject-matter of the dispute,” the first time it has been so rejected on the ground of absence of consent.  I understand the line of their analysis but, in my view, when the States Parties to a BIT contingently consent,  inter alia, to ICSID jurisdiction, the consent  component of Article 46 of the Washington Convention is  ipso facto imported into any ICSID arbitration which an investor then elects to pursue. It is important to bear  in mind that such counterclaim jurisdiction is not only a concession to the State Party: Article 46 works to the benefit of both respondent state and investor. In rejecting ICSID jurisdiction over counterclaims, a neutral tribunal – which was, in fact, selected by the claimant – perforce directs the respondent State to pursue its claims in its own courts where the very investor who had sought a forum outside the state apparatus is now constrained to become the defendant. (And if an adverse judgment ensues, that  erstwhile defendant might well transform to claimant again, bringing another BIT claim.) Aside from duplication and inefficiency, the sorts of transaction costs which counter-claim and set-off procedures work to avoid, it is an ironic, if not absurd, outcome, at odds, in my view, with the objectives of international investment law.