Fallacies of False Generalization
With fallacies of false generalization, or defective inductions, assumptions are made about people or things that may not necessarily apply to the situation at hand. In the case of Abu Ghraib and other morally ambiguous scenarios, the justification the soldiers may have had falls along these lines. By placing these terror suspects in cramped cells, and attributing some of the worst aspects of who they were hunting to everyone at the base, the soldiers there made a false generalization that everyone there was a terrorist and did not deserve human respect. By generalizing these prisoners based on their mere presence inside the facility, they assumed they were terrorists or at least indirectly responsible for terror attacks on the United States, including the 9/11 attacks, and thus deemed them all unworthy of human dignity. No distinction was made between those who were there for political reasons and those who were potential enemy combatants, which led to widespread dehumanization of the prisoners as the soldiers saw them as less than human. The documentary also infers that because these particular soldiers are bad, the American presence in Iraq was inherently bad - there would have to be more evidence to cement that claim than this singular incident.
Causal fallacies state that, because one thing happens after another thing, the latter causes the former. In the case of Abu Ghraib, one assumption is made that the soldiers committed these acts of abuse and torture because of the adverse conditions at Abu Ghraib - therefore, the adverse conditions led them to perform these actions. However, this is a causal fallacy; just because the conditions were horrible - one soldier describes the awful smell of the prison, while another notes the presence of death chambers and ovens for incineration as causing "displaced souls" - that these soldiers chose to behave uncharacteristically. While these may or may not be contributing factors, these conditions alone do not remove free will from the soldiers of Abu Ghraib; societal and cultural conditions, as well as their own choices, were the direct cause of prisoner abuse and torture. As a result, it must be said that the claims of uncharacteristic behavior as a result of the horrible conditions of Abu Ghraib cannot be said to directly cause the actions the soldiers took.
Fallacies of Relevance
Fallacies of relevance include trying to prove a point through factors and citing of circumstances that have nothing to do with the truth of a particular claim. With Abu Ghraib, the soldiers cite the consequences of potentially not torturing the prisoners as being worse than when they had. To many, torturing the prisoners was seen as a necessary evil to extract needed information that would allow US military personnel to target terrorist cells and other groups. However, since the consequences of these acts were not known, that cannot be used as justification for said torture - that potential outcome is irrelevant to the subject at hand. When presenting this fallacy, people are using hypotheticals to obfuscate the real matter being discussed - whether or not the Abu Ghraib torture was justified. In the case of the Abu Ghraib soldiers, it is necessary to note that the ends do not justify the means; to claim otherwise is a fallacy of relevance.
Ghosts of Abu Ghraib.
The Lucifer Effect - Understanding How Good People Turn Evil.