A puzzling question is why the Bush administration stubbornly opposes Sen. John McCain’s amendment that would ban abusive treatment of prisoners in American custody. And why has Vice President Dick Cheney tried so hard to persuade the Arizona Republican to exempt the Central Intelligence Agency from the restrictions on torture?

Part of the answer seemed to emerge in a sensational expos? by The Washington Post of a secret global prison system operated by the CIA in at least eight countries including Afghanistan, Thailand, several democracies in Eastern Europe, and a small center at the Guantanamo Bay prison in Cuba. The Post said it was withholding the names of Eastern European countries involved in the secret program at the request of senior U.S. officials.

Rough outlines of the hidden prison system had emerged earlier in reports that some high-level terrorist suspects had been sent off to undisclosed destinations for indefinite detention and interrogation in a procedure known as “rendition.” Parliamentary inquiries are said to have been opened in Canada, Italy, France, Sweden and the Netherlands into allegations that their citizens or residents had been sent to secret CIA prisons.

The newspaper reported that the CIA interrogators at the so-called “black sites” are permitted to use approved “enhanced interrogation techniques,” some of which are prohibited by U.S. military law and international agreements. It said these methods include “waterboarding,” in which a prisoner is made to believe he or she is drowning.

The International Committee of the Red Cross, the European Union and human rights groups have said they would request information about the secret prisons from the United States and reported host governments.

Pursuing the story, the Post reported this week that Vice President Cheney had been waging an intense but largely unpublicized campaign to stop Congress, the Pentagon and the State Department from imposing more restrictive rules on the handling of terrorist suspects. The newspaper described a deepening split between Mr. Cheney and Defense Secretary Donald Rumsfeld on one side and certain uniformed military leaders and Secretary of State Condoleezza Rice on the side of increasing safeguards against prisoner abuse.

Prisoner abuse is nothing new in wartime, but condoning it officially is bad policy for at least two reasons. First, it violates basic principles of conduct held by most Americans and agreed to by international conventions. Secondly, if the United States is known to abuse prisoners, Americans who are captured are more likely to be abused.

The Bush administration should welcome the McCain amendment, already approved twice by the Senate – first by a 90-to-9 vote and last week unanimously. And the administration should clean out those secret prisons and rely on the American system of justice to bring prisoners to trial, punish the guilty and free the innocent.