Predictably, Congress is divided along partisan lines about how to respond to the abuse at Abu Ghraib. Many Democrats want an investigation; many Republicans don't. Is there a role for Congress to play here?

There is a desperate need for congressional oversight. There should be an investigation as well as hearings. It is clear that the Bush administration is not adequately policing itself. The administration has known since probably December that there was a serious problem here, and it simply covered it up. It took some steps to address it by recommending court-martials against the six soldiers involved, and Karpinski was relieved of her command. But there is no evidence that the Bush administration looked seriously at the interrogation methods that were being authorized for use by the CIA, by military intelligence and by private contractors.

It was hard to miss the irony this week. As we heard more about the mistreatment of prisoners at Abu Ghraib, we learned that Thomas Hamill -- the American contractor taken hostage in Iraq -- was treated well by his captors. Pvt. Jessica Lynch was also apparently treated well during her captivity in Iraq. Is there a case to be made that the Iraqi "evildoers" are treating Americans better than Americans are treating some Iraqis?

I don't know that I'm in the position to make that case. But let me make two points. One is that the duty to avoid torture or cruel, inhumane and degrading treatment or punishment is an absolute duty. So even if the other side is violating that rule, the United States still has an absolute duty to abide by it. And indeed, failure to abide by it is a criminal offense punishable any place in the world.

That's one thing to remember. Second, when we have rules like this, it's not simply for fighting against what may be a largely lawless insurgency in Iraq. One has rules because they apply around the world. The United States should be very reluctant to lower the bar on international standards. Imagine a future war with, say, China over Taiwan. The Chinese government is already beginning to question whether the laws of armed conflict are really just Western impositions, whether these are things that should bind China as well. In a possible future war, if American service members are taken into Chinese custody, you don't want to give the Chinese government an excuse to start mistreating them in detention under the theory that Donald Rumsfeld already authorized these "stress and duress" interrogation techniques.

So this is not only a matter of living up to American values of treating others properly. There's also a direct element of self-interest in this. American service members are going to suffer if Bush and Rumsfeld essentially vitiate the basic norms of the Geneva Conventions and other elements of international law.

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