This Chapter argues, that documentary as well as non-documentary evidence can be used to build a case of command responsibility for atrocity crimes by the American forces in Iraq, and which in turn can set the foundation and increase the possibility for war of aggression charges against the United States. The atrocity crimes that we focus on were committed during the American-led invasion and occupation of Iraq and consist of detention and torture. We demonstrate the criminal intent of the Bush Administration, and seek to show that they intentionally redefined torture as legal with the purpose of engaging in criminal acts of torture to gather evidence of suspected threats in order to provide justification for waging a preemptive war in Iraq. We then seek to illustrate how a widespread detention policy was combined with the criminal use of torture by U.S. military forces and the new U.S.-supported Iraq Ministry of Interior security personnel. Finally, we argue that the investigation and development of evidence of these atrocity crimes can further set the foundation for war crimes charges, initiating a process that can lead ultimately to charges of aggressive war against the United States.