The Principles of International Law, recognized in the Charter of the Nuremberg Tribunal and in the Judgment of the Tribunal, provide no defense for war crimes. Similarly, the Convention Against Torture, which defines torture as a war crime, provides that “no exceptional circumstances whatsoever, whether a state of war or a threat of war, internal political instability or any other public emergency, may be invoked as a justification for torture.”
"Failure to prosecute Bush era war criminals
In the run-up to the 2008 election Obama recognized how the past casts a long shadow across history. Referring to slavery and racial injustice, he paraphrased William Faulkner’s: “The past is never dead. It’s not even past.” Nevertheless, from the beginning Obama condoned the Bush-era war crimes by not prosecuting Bush officials and by appointing many Bush-era officials to his administration. Before he was even inaugurated, Obama opposed any investigations citing "a belief that we need to look forward as opposed to looking backwards." Indeed, he has both granted amnesty to the CIA agents involved in torture and offered legal defense against prosecution from any quarter."