In this report Amnesty International expresses concerns about the United States administration’s attempt to persuade Congress to narrow the scope of the US War Crimes Act to prevent prosecutions of US personnel for humiliating and degrading treatment of detainees in the "war on terror". These discussions follow the Hamdan v. Rumsfeld ruling of the US Supreme Court on 29 June 2006. In the Hamdan decision, the Supreme Court overturned a central tenet of the executive’s "war on terror" policy. In a case involving the armed conflict in Afghanistan, it ruled that Article 3 common to the four Geneva Conventions of 1949 – which prohibits torture, cruel, humiliating or degrading treatment – applied. In his concurring opinion, Justice Kennedy noted that under the War Crimes Act, violations of common Article 3 are war crimes. Amnesty argues that that any measure to narrow the scope of the War Crimes Act would undermine the rule of law and send a dangerous message about impunity.