 where the acceptance of international law by a constitutional democracy can be reasonably expected to result in constitutional changes—significant alterations in constitutional structures or significant diminutions in political self-determination—then, as with other constitutional changes (such as consensual secession, accession to a federation, or devolution from a centralized state), there is a strong presumption that public constitutional deliberation and popular choice are required. (Buchanan &amp; Powell 2008: 347)