Here's a link to Seymour Hersh's excellent New Yorker article based on several interviews with Gen. Antonio Taguba, who was assigned by the military to investigate possible abuse and torture at Abu Ghraib prison, and some other reporting. Gen. Taguba did an excellent job, but when he was called to meet then-Defense Sec. Rumsfeld and other top brass, Rumsfeld greeted him in a mocking manner: "Taguba, describing the moment nearly three years later, said sadly, 'I thought they wanted to know. I assumed they wanted to know. I was ignorant of the setting.'"
Taguba's assignment was narrow: he was told not to follow the abuse up the chain of command, just to discover who had done it. But he's sure responsibility lies higher up than the few enlisted personnel and one officer who were punished. "Those M.P. troops were not that creative. Somebody was giving them guidance, but I was legally prevented from further investigation into higher authority. I was limited to a box." He certainly doesn't think Rumsfeld was frank as to what he knew and when he knew it.
Having documented abuse , even though he didn't investigate up the chain of command. Gen. Taguba was (what did you expect?) punished. He "had been scheduled to rotate to the Third Army's headquarters, at Fort McPherson, Georgia, in June of 2004. He was instead ordered back to the Pentagon, to work in the office of the Assistant Secretary of Reserve Affairs. 'It was a lateral assignment,' he said with a smile and a shrug. 'I didn't quibble. If you're going to do that to me, well, O.K. We all serve at the pleasure of the President. ' A retired four-star Army general later told Taguba that he had been sent to the job in the Pentagon so that he could 'be watched.' Taguba realized that his career was at a dead end.'"
He has since retired. Personal and institutional integrity don't seem to be rewarded very consistently in our military.