The UK Supreme Court's much-anticipated judgment in Halliburton Company (Appellant) v Chubb Bermuda Insurance Ltd (formerly known as Ace Bermuda Insurance Ltd) (Respondent) [2020] UKSC 48 (on appeal from [2018] EWCA Civ 817) opens with the recognition of an axiom which goes to the heart of justice: 'it is axiomatic that a judge or an arbitrator must be impartial; he or she must not be biased in favour of or against any party in a litigation or reference.' After restating the law on the extent to which an arbitrator can, without disclosure and without giving rise to an appearance of bias, accept appointments in multiple references concerning the same or overlapping subject matter with only one common party, the judgment concludes that the arbitrator in question was in breach of a legal duty of disclosure but that, on the facts, he did not need to be removed. With that conclusion, many in the international arbitration community may well wonder whether the 'axiomatic' duty has been given sufficient bite.