It turns out that those who embraced, authorized or otherwise accepted our entry into the Torturers’ League of Nations knew not what they did:

The program began with Central Intelligence Agency leaders in the grip of an alluring idea: They could get tough in terrorist interrogations without risking legal trouble by adopting a set of methods used on Americans during military training. How could that be torture?

In a series of high-level meetings in 2002, without a single dissent from cabinet members or lawmakers, the United States for the first time officially embraced the brutal methods of interrogation it had always condemned.

This extraordinary consensus was possible, an examination by The New York Times shows, largely because no one involved — not the top two C.I.A. officials who were pushing the program, not the senior aides to President George W. Bush, not the leaders of the Senate and House Intelligence Committees — investigated the gruesome origins of the techniques they were approving with little debate.

According to several former top officials involved in the discussions seven years ago, they did not know that the military training program, called SERE, for Survival, Evasion, Resistance and Escape, had been created decades earlier to give American pilots and soldiers a sample of the torture methods used by Communists in the Korean War, methods that had wrung false confessions from Americans.

Even George J. Tenet, the C.I.A. director who insisted that the agency had thoroughly researched its proposal and pressed it on other officials, did not examine the history of the most shocking method, the near-drowning technique known as waterboarding.

The top officials he briefed did not learn that waterboarding had been prosecuted by the United States in war-crimes trials after World War II and was a well-documented favorite of despotic governments since the Spanish Inquisition; one waterboard used under Pol Pot was even on display at the genocide museum in Cambodia.

They did not know that some veteran trainers from the SERE program itself had warned in internal memorandums that, morality aside, the methods were ineffective. Nor were most of the officials aware that the former military psychologist who played a central role in persuading C.I.A. officials to use the harsh methods had never conducted a real interrogation, or that the Justice Department lawyer most responsible for declaring the methods legal had idiosyncratic ideas that even the Bush Justice Department would later renounce.

The process was “a perfect storm of ignorance and enthusiasm,” a former C.I.A. official said.

Today, asked how it happened, Bush administration officials are finger-pointing. Some blame the C.I.A., while some former agency officials blame the Justice Department or the White House.

Why should this have worked any differently from everything else the Bush administration did? Nobody exercised due diligence. Nobody asked any questions. Because everybody assumed that someone else must have asked the right questions at some point.

But all this gives rise to some interesting questions now. When did that most honorable warrior, Gen. Colin Powell, for example, first learn the truth about waterboarding? What did he then do or not do?

Forget not knowing about the origins of SERE, or the history of waterboarding. At some of those meetings that Colin Powell did attend, where they got into the nitty gritty of who was authorized to do exactly what and to whom, they surely talked about the fact that we were planning to force detainees to stay awake for more than a whole week? Surely, it should have struck someone that such extreme sleep deprivation constitutes crossing the line?

“We weren’t told” really cannot constitute a defense for everything these good folks signed off on.