Dick Cheney, the departing vice-president, said he did not see how Guantanamo could be responsibly closed until the "war on terror" was over. He also tried to justify using "water-boarding" on some detainees during interrogation. He said the technique, which simulates drowning, was an appropriate means of extracting information from suspects such as Khalid Sheikh Mohammed, the alleged mastermind of the 11 September attacks.