By Eugene Robinson - April 24, 2009

WASHINGTON -- The many roads of inquiry into the Bush administration's abusive "interrogation techniques" all lead to one stubborn, inconvenient fact: Torture is not just immoral, but also illegal. This means that once we learn the whole truth, the law will oblige us to act on it.

Understandably, the Obama administration wants to avoid getting bogged down in a long, wrenching legal drama that almost certainly would be partisan and divisive. But I'm not sure it's possible to skirt the criminal implications of what we already know, let alone what we might find out in a full-scale "truth commission" investigation with access to all relevant witnesses and documents.

On the moral question, the administration has been straightforward and righteous. One of President Obama's first acts was to declare that the United States will no longer practice waterboarding or other abusive interrogation methods, saying that such depredations are inimical to our nation's values and traditions. Attorney General Eric Holder stated at his confirmation hearings that "waterboarding is torture." This refreshing and admirable clarity stands in stark contrast to the fog of legalistic sophistry in which the Bush administration cloaked its secret prisons.

On the legal question, though, the Obama team has been far less definitive. This is what Dennis Blair, the director of national intelligence, told his staff about the interrogation abuses in a memo last week: "I like to think I would not have approved those methods in the past, but I do not fault those who made the decisions at that time, and I will absolutely defend those who carried out the interrogations within the orders they were given."

To state the obvious, this makes no sense at all. If Blair would not have sanctioned "those methods" -- some of which clearly meet the legal definition of torture, in my view -- then why would he give a pass to those who ordered the abuses and those who carried them out?

At least Blair, charged with leading the agents who performed the abuses, has a reason for going all fuzzy on the matter of accountability. And we can thank him for definitively refuting the most commonly cited pro-torture argument: that waterboarding, sleep deprivation, stress positions and other abuses were necessary to obtain vital information that kept Americans safe from another al-Qaeda attack.

"High value information came from interrogations in which those methods were used," Blair wrote in the memo. But in a separate statement, he added that "there is no way of knowing whether the same information could have been obtained through other means."

This should be obvious. Yes, people break under torture and tell what they know, along with what they don't know and what they think their torturers want to hear. But there is no way to be certain that the valuable information wouldn't have been extracted through traditional -- and legal -- methods of interrogation.

Even if experts have differing views about torture's effectiveness, there is one point on which they cannot disagree: It violates U.S. and international law.

What abuses legally qualify as torture? That probably depends on which of several possibly applicable legal standards is applied. At a bare minimum, though, it seems clear to me that waterboarding will almost certainly be deemed illegal if put under judicial scrutiny. The practice has been considered torture at least since the Spanish Inquisition -- except, apparently, in the Office of Legal Counsel under George W. Bush.

I don't know what more we'll find out if a blue-ribbon investigative panel of some kind is formed. But what we already know is enough to ensure that sooner or later, the abusive interrogation methods authorized by George W. Bush, Dick Cheney and other officials are going to be measured against the law. Our system, left to its own devices, is not designed to let illegal acts be revealed and then ignored.

From the viewpoint of the Obama administration, the alternatives may be unattractive or even unacceptable. No one wants to see low-ranking CIA interrogators go down for doing what their superiors told them was legal, especially if the superiors are not held to account. But pursuing criminal charges against the highest-ranking officials of the previous administration would be unprecedented, and it is unclear where such a process might lead.

It will be hard to stop this train, though. The rule of law is one of this nation's founding principles. It's not optional. Our laws against torture demand to be obeyed -- and demand to be enforced.