Let's get to the top of Abu Ghraib

Army Pfc. Lynndie England, of the smiling, pointing Abu Ghraib prison photos, has been sentenced to three years behind bars for her part in the abuse of Iraqi prisoners and detainees at the now-notorious military prison in Iraq. Although she could have received nine years, the three-year sentence seems appropriate.

There is no excuse for what she did, and the stain she and others put on the honor of the U.S. military will take a long time to fade. But she doesn't seem to have been a ringleader, just somebody who went along with (and eventually seemed to enjoy) deeply shameful activities.

This should not be the end of the story, however. Nine low-level soldiers have been court-martialed for their parts in this scandal. Now it is important to get to the bottom - or the top - of why this happened.

A brave young soldier is trying to jump-start inquiries into how it became almost routine to abuse Iraqi detainees in U.S.-run military prisons. Capt. Ian Fishback, 26, a West Point graduate described by friends as "a deeply religious Christian and patriot who prays before each meal and can quote from the Constitution," served two tours of combat duty, in Afghanistan and in Iraq. He has encountered mostly frustration during the 17 months he has been trying to determine what standards apply to prisoner treatment in Iraq. Now it's time for a breakthrough.

In a letter to Arizona Republican Sen. John McCain, Capt. Fishback, who has been sequestered at Fort Bragg, N.C., on the grounds that he is a key witness in an ongoing investigation and should not be in contact with outsiders, describes how his inquiries up the chain of command led to no clear, consistent answers. "I am certain that this confusion contributed to a wide range of abuses," he wrote, "including death threats, beatings, broken bones, murder, exposure to the elements, extreme forced physical exertion, hostage-taking, stripping, sleep deprivation and degrading treatment. I and troops under my command witnessed some of these abuses in both Afghanistan and Iraq."

Theories abound as to how this could have happened, including winking, nodding and the tacit condoning of torture and near-torture by the White House. It is time for a hard-nosed inquiry. Will Sen. McCain initiate it? Please.