WASHINGTON – When high-ups at Central Intelligence Agency headquarters ordered the torture of Abu Zubaydah, they thought he had been withholding valuable information.

There was no ticking time bomb, and no one ever claimed there was. They just thought he knew more than he was saying about al-Qaeda.

I call it torture because that's what near-drowning at the hands of interrogators was until 2002, when President George W. Bush's lawyers claimed otherwise. That's also what it was after they left office this year.

Some "enhanced interrogation techniques," which lawyers in the White House, the Justice Department and the Defence Department declared legal, were the same ones Chinese communists used when trying to squeeze false "confessions" from American prisoners during the Korean War.

In fact, that's how the US military knew about the methods, according to an exhaustive Senate Armed Services Committee report released this week.

Pouring water up a prisoner's nose until he almost drowns, stripping him naked, isolating him, keeping him awake for days, forcing him to maintain painful poses, that was all part of various enemies' torture playbooks, which the U.S. military used as guidance.

Employed during the Spanish Inquisition and favored by Cambodia's murderous Pol Pot regime, waterboarding is especially useful as it induces terror while leaving no mark. Civilised countries like the US considered it torture and prosecuted its practitioners.

That thinking held true until Bush's gang of lawyers wrote secret memos declaring waterboarding and other acts of cruelty just fine by them as means to elicit information from suspected terrorists. The attacks of September 11 and the need to prevent others drove them to justify that which had previously been unjustifiable.

When Bush explained years after the fact why the CIA ratcheted up Zubaydah's interrogation, he said it was because the man had "stopped talking".

"As his questioning proceeded, it became clear that he had received training in how to resist interrogation," Bush said at a 2006 press conference.

That's one theory. The CIA interrogators who had been questioning Zubaydah believed another. They figured he stopped talking because he had nothing else to say.

Already he had named Khalid Sheikh Mohammed an architect of the 2001 terrorist attacks. And it hadn't taken waterboarding to get it out of him, sources involved in the interrogation told the New York Times. An FBI agent who questioned Zubaydah confirmed that in an op-ed piece in the Times this week.

After 83 waterboardings, Zubaydah pleaded for his life but offered no new information, according to the Times' account.

Former CIA Director Michael Hayden disputes that version, saying Zubaydah gave out only tidbits until the CIA ratcheted up its methods.

It's easy, on a "bright, sunny, safe day in April 2009", as Director of National Intelligence Dennis Blair wrote last week, to judge those who were trying to protect the country against another attack like the one of September 11, 2001.

And yet, they make it so hard not to.

Lawyers from every branch of the military complained about the legally specious grounds for the torture memos, the "profound mistakes" in them, as Navy General Counsel Alberto Mora put it.

Time and again they were rebuffed and found themselves cut out of the discussion.

The chief argument to support the torture is no longer legal but practical. Torture works, say Bush administration defenders, and it saved American lives.

If Dick Cheney gets his way, and I hope he does, the military will release more information about the torture programme. What fruit did it bear?

Unless there's a line between a specific, murderous, imminent plot stopped that probably couldn't have been halted without torture, Cheney will have a hard time justifying using torture, given its consequences.

Al-Qaeda had no more powerful recruiting poster than images from Abu Ghraib. The endless imprisonments of detainees at Guantanamo Bay and the now-confirmed reports of torture there have cost the US its claim to be a protector of human rights.

Beyond the suffering it inflicts on its targets, torture can render detainees unprosecutable. Zubaydah's former prosecutor acknowledged she had to drop charges against him, for example.

And then there are all those lies.

In spite of administration efforts to paint the horrific abuses at Abu Ghraib as the work of a few sadistic rogues, the Senate report laid at least indirect blame on former Defence Secretary Donald Rumsfeld.

The techniques he approved "conveyed the message that physical pressures and degradation were appropriate," the report says.

They weren't before September 11, 2001. And they aren't now.

Ann Woolner is a Bloomberg News columnist.