The pictures of Iraqi prisoners being tormented and humiliated are appalling, as are the incidents (third item) they record. Appalling and inexcusable. They are also a betrayal, by those responsible, of the aims of the Coalition in Iraq. That responsibility is shared between the soldiers actually involved in treating the prisoners in so brutal a way and whoever is directly accountable for the internal prison regime in which this treatment was allowed to occur. It is to be hoped all concerned will be made to answer, to pay the appropriate penalty, for what they've done.
Round and about the comments boxes today I've seen some speculation of a would-be sociological kind as to what sort of factors might explain these abuses. I don't pretend to offer an explanation myself. I simply outline here one piece of academic research that is relevant, or so it strikes me. This does not exonerate anyone - a point to which I'll return.
There is a famous experiment, conducted under the direction of Philip Zimbardo, in which student volunteers - screened to eliminate overly aggressive or cruel people - were invited to play the roles of prisoners and guards, with the volunteers all ignorant, at the point of volunteering, of which would be their own role. The guards were to enforce certain rules without the use of physical violence, but they were otherwise free to exercise their discretion. The results? Some 'guards' were firm but fair; others, however, began to behave in aggressive and sadistic ways, resorting to creative forms of cruelty and harassment, insults, humiliation and so forth. Several 'prisoners' had to be released from the experiment early on, suffering from severe depression; and the experiment itself was terminated before it had run its course, because those overseeing it became alarmed at what was developing in the playing out of these roles.
The results tie in with those from the famous experiments carried out by Stanley Milgram, in showing that irrespective of any wider background sociological influences, micro-situational factors also matter. People with immediate power over others may be tempted to abuse it. Not all, but some, of them. Drawing attention to this does not exonerate anybody. It does not excuse or mitigate. On the contrary, it shows there is a body of knowledge, available to anyone in charge of a regime of incarceration, sufficient to have alerted those responsible for the Abu Ghraib prison regime to the need to have precautions and restraints in place against the very contingency of what took place there. The research also shows, as does the case of the Abu Ghraib incident itself, that there are nearly always actors in the micro-vicinity who do not fall in with such abuses, so giving the lie to excuse-making forms of 'understanding'.
(See the article by Craig Haney, Curtis Banks and Philip Zimbardo, 'Interpersonal Dynamics in a Simulated Prison', International Journal of Criminology and Penology 1, 1973, pp. 69-97.)