This article presents a methodological critique of the interpretation, increasingly popular after Hassan v UK, that Article 5(1) ECHR allows the internment of prisoners of war or civilians in international armed conflicts according to international humanitarian law because state parties to the ECHR have been conducting such practice without derogation from it. First, the probative value of the
... [Show full abstract] non-derogation is discounted by the fact that such practice is not in application of Article 5(1) ECHR. Second, it is difficult to establish interpretive agreement among parties because of the uncertainty of the non-derogating parties’ beliefs, the uncertainty of the other parties’ awareness of those beliefs and the lack of acceptance and confirmation. Third, the probative value of any seeming acquiescence to such practice is undermined by the lack of incentives for states to challenge other states’ practice, the practical obstacles to launching such challenges and the dissent of human rights beneficiaries.