… Evidence of Torture:
Evidence of G.W. Bush’s complicity in torture is overwhelming. As stated by Maj. General Antonio M. Taguba, author of the U.S. Army’s 2004 internal report on Abu Ghraib,
“… the Commander-in-Chief [Bush] and those under him authorized a systematic regime of torture…. After years of disclosures by government investigations, media accounts, and reports from human rights organizations, there is no longer any doubt as to whether the current [Bush] administration has committed war crimes. The only question that remains to be answered is whether those who ordered the use of torture will be held to account.”
Many people aware of the evidence and the law have concluded that the available evidence establishes conclusively that George W. Bush and other members of the Bush Administration committed torture (and other war crimes and crimes against humanity) and therefore states now have a duty to condemn, investigate, prosecute and punish those crimes. Following are a sample of conclusions and remarks by a variety of such people. Comprehensive lists of evidence are readily available from a variety of sources and will be provided on request.
In July 2004 the International Committee of the Red Cross concluded that the American military had used interrogation techniques tantamount to torture on prisoners in Guantánamo Bay.
In a February 2006 report, a group of UN experts concluded that sleep deprivation for several consecutive days, enforced isolation, the use of dogs, and exposure to extreme temperatures were all being used at Guantánamo Bay prison by US officials and that these interrogation methods met all five elements of torture (perpetrated by government official, had a clear purpose, committed intentionally, victims in a position of powerlessness and caused severe physical or mental pain or suffering.)
In May 2006, the UN Committee on Torture called on the US to close Guantánamo Bay prison, to eradicate the use of torture by military and civilian personnel and to rescind authority to use any interrogation method that constitutes torture or cruel, inhuman or degrading treatment or punishment.
In June 2007 the Council of Europe Parliamentary Assembly report by Senator Dick Marty concluded that
“the CIA [the US Central Intelligence Agency] committed a whole series of illegal acts in Europe by abducting individuals, detaining them in secret locations and subjecting them to interrogation techniques tantamount to torture.
In December 2008 the US Senate Armed Services Committee concluded,
“senior officials [Bush and others] in the United States government solicited information on how to use aggressive techniques, redefined the law to create the appearance of their legality, and authorized their use against detainees.”
In January 2009 Manfred Nowak, then the UN Special Rapporteur on Torture said,
“The evidence is sitting on the table…There is no avoiding the fact that this was torture… The government of the United States is required to take all necessary steps to bring George W. Bush and Donald Rumsfeld before a court.”
In February 2009, UN Special Rapporteur Martin Scheinin reached the same conclusion,
“…the United States has created a comprehensive system of extraordinary renditions, prolonged and secret detention, and practices that violate the prohibition against torture and other forms of ill-treatment….States must not aid or assist in the commission of acts of torture, or recognize such practices as lawful, …Under international human rights law, States are under a positive obligation to conduct independent investigations into alleged violations of the right to life, freedom from torture or other inhuman treatment, enforced disappearances or arbitrary detention, to bring to justice those responsible for such acts, and to provide reparations where they have participated in such violations.” (underlining added)
On March 4 2009, then UN General Assembly President Miguel d’Escoto Brockmann, on March 4, 2009 concluded,
“The [Bush Administration] aggressions against Iraq and Afghanistan and their occupations constitute atrocities that must be condemned and repudiated by all who believe in the rule of law in international relations,”
In May 2009 former Vice President Dick Cheney publicly stated that George W. Bush authorized the use of torture,
“ I mean it was a presidential-level decision. And the decision went to the president. He signed off on it.”
In his 2010 memoirs, George W. Bush admitted to authorizing the use of interrogation techniques that constitute torture such as water boarding. 
In February 2011 Bush cancelled a trip  to Switzerland because he faced the risk of prosecution for torture. Human Rights groups had called on the Swiss government to arrest him and open a criminal investigation if he entered the country citing Switzerland’s legal obligations under CAT. The New York-based Center for Constitutional Rights and the Berlin-based European Center for Constitutional and Human Rights, backed by many others—released and threatened to file a 45-page indictment backed up by a 2,500 page summary of evidence of Bush’s role in authorizing, directing and supervising torture used at U.S. controlled prison including Bagram Afghanistan, Abu Ghraib, Iraq and Guantanamo Bay Cuba. 
Reed Brody of Human Rights Watch commented, “I’m surprised he (Bush) would even consider visiting a country that has ratified the torture convention and which takes its responsibilities seriously.”
In June 2011 Human Rights Watch published an extensive report concluding that members of the Bush administration had used torture and should be prosecuted. 
Duty to prosecute: … (full long text and notes 1 – 21).