[3] Following her education, Higgins was a practising barrister, and became a Queen's Counsel (QC) in 1986, and is a bencher of the Inner Temple.

Her role as member of the leading body for supervising implementation of the International Covenant on Civil and Political Rights earned her respect for her diligence and competence.

Despite delivering many balanced judgements in different cases, Higgins's dissenting opinion in the ICJ's advisory opinion on the Legality of the Threat or the Use of Nuclear Weapons has been widely criticised by some legal scholars, on the grounds that it provides sovereign states with an unjustifiable amount of latitude in resort to the use of nuclear weapons in times of armed conflict.

[4] In October 2009 she was appointed advisor on International Law, to the British government's inquiry into the Iraq war (Headed by Sir John Chilcot).

Her competence has been recognised by many academic institutions, having received at least thirteen honorary doctorates, as well as the Yale Law School Award of Merit[3] and also the Manley-O.-Hudson medal.