IN R. (Lord Carlile) v Secretary of State for the Home Department [2014] UKSC 60; [2014] 3 W.L.R. 1404, the Supreme Court held by a four to one majority (Lords Sumption, Clarke, Neuberger and Lady Hale, Lord Kerr dissenting) that the exclusion of an Iranian dissident from the UK was a proportionate interference with the Article 10 ECHR right to freedom of expression of both the dissident herself and the cross-party group of parliamentarians litigating on her behalf. The parliamentarians had wished to invite Mrs. Maryam Rajavi, the exiled leader of the former terrorist group the People's Mojahedin Organisation of Iran, to the Palace of Westminster to speak about democracy and human rights in Iran. The Home Secretary had excluded the invitee on the basis of a risk assessment formulated in cooperation with the Foreign Office. The risk assessment had concluded that admission of Mrs. Rajavi might endanger foreign relations between Britain and Iran, and British national security because of the potential risk to the safety of British diplomatic personnel based in Iran. Lord Sumption put the matter succinctly: “the future is a foreign country” and the Courts should therefore be reticent to interfere with Executive predictions in the realm of “high policy” (at para. [46]). The judgment is of great interest not only for its background facts, which concern the often fraught and complicated diplomatic relationship between the UK and Iran, but principally because the decision engages central constitutional questions regarding the institutional competence of the courts in judicial review.