War and armed conflict — Geneva Conventions of 1949 — Common Article 3 and Article 17 of Geneva Convention III — Prisoners of war — Interrogation techniques — Judicial review of Secretary of State’s policy authorizing questioning of captured persons — Whether policy giving rise to unacceptable risk of inhumane treatment, threats, insults, or unpleasant or disadvantageous treatment — Whether policy compatible with the United Kingdom’s obligations under international law — The law of England