There is no excusing the kind of abuses of Iraqi war prisoners Americans are learning about this week. It’s hard to imagine an American, from the most idealistic college student to the most battle hardened military man, who is not appalled and angered by the crimes being disclosed. They are going to be a blot on America’s name on the order of, say, the massacre at My Lai in Vietnam. To those of us of a certain age, who remember the efforts by the top brass to cover up the crimes at My Lai, one of the remarkable elements of this unfolding story is the role of America’s own military, from low-ranking soldiers to four-star generals, as the driving force in uncovering the scandal at Abu Ghraib.

This is suggested by Seymour Hersh of the New Yorker, which posted an account on Saturday. He reports that long before the press got onto the story, the top American Army officer in Iraq, General Sanchez, had authorized a major investigation into the Army’s prison system that resulted in a 53-page report. It was obtained by Mr. Hersh and is devastating. Mr. Hersh reports that the abuses became public because of the outrage of a military policeman, Specialist Jos. M. Darby, who, one government witness told a military court, had come across pictures of naked detainees. “He felt very bad about it and thought it was very wrong,” a military court was told.

The promptness with which the military began investigating these abuses and acting to stop them marks a change from an earlier time. Charlie Company of the 11th Brigade of the Americal Division slew the more than 500 people it killed at My Lai on March 16, 1968. It wasn’t until November 1969 that word of the massacre reached the American public, thanks in large part to a former GI, Ron Ridenhour, who told the story to Mr. Hersh. Mr. Ridenhour had already written to everyone from the Pentagon and Congress to President Nixon himself, without effect. And even once the story was public, enormous resistance was mounted to a vigorous prosecution. It’s hard to imagine President Bush or any senior member of his administration trying, or even desiring, to mount the kind of cover-up attempted years ago.

Not that this fact is going to stop the anti-war faction from using this scandal in its campaign for an American retreat. One war critic, Paul Craig Roberts, gloated in a column posted Friday that Mr. Bush “describes our mission as one in which our troops are dying and we are spending hundreds of billions of dollars not to acquire a colony or to control the oil, but to liberate Iraqi women and to make Iraqis safe from torture.

With the U.S. now guilty of war crimes as defined by Article 3 of the Geneva Convention, our sanctimonious president will never again be able to wear American virtue on his sleeve without the entire world laughing in his face.”Another anti-war blogger, Joshua Marshall, promises discussion to come on “a slew of new news…from the still-emerging scandal over the torture of Iraqi prisoners to the withdrawal from Fallujah, to the lies of the president who, at root, made all of this possible.”

Amnesty International is rushing out charges that the abuses are systematic, though that is all too typical of Amnesty International, which has long since sacrificed its credibility to its left-wing politics.

The right thing going forward is for the Bush administration to press ahead ruthlessly with the investigation its officers started before any of this hit the press and to bring the culprits to justice.

That will be a lot more than happens to those who abuse prisoners in the Arab regimes who are reported to be so scandalized by the latest disclosures.

And to press ahead, too, with the capture and interrogation of enemy soldiers, agents, and collaborators, as aggressively as the laws of war and of America permit, so that the battle of Iraq ends in a victory.