The defining moments of 2001, the terrorist attacks of September 11 against the UnitedStatesofAmerica,markedaturningpointininternational lawandrelations. Bytheirscaleandaudaciousness, overnighttheyhelpedtopropeltheissueofint- national terrorism to the top of the international security agenda and particularly that of the USA, with consequences for many branches of international law, including the jus ad bellum, the jus in bello, international law relating to terrorism, international human rights law and international criminal law, that were just beginning to be felt as the year closed. The September 11 attacks were immediately characterised by the United States 3 as an act of war,an armed attack on such ascale asto constitute an armed conflict. Its immediate response was to declare a so-called Global War on Terrorism . Avowedly acting in self-defense, on 7 October the US launched armed attacks against Afghanistan, notbecause Afghanistan wasconsidered tobelegally resp- sible for the September 11 attacks but for harbouring and refusing to surrender members of Al Qaeda, including its leader, Osama Bin Laden, and refusing to dismantle terrorist training camps. Although the main target of the attacks was Al Qaeda, the armed conflict that ensued was an international armed conflict between the US and its allies and the state of Afghanistan, notwithstanding that the US never recognised the Taleban as the government of Afghanistan.