Without the underlying documents, it’s not possible to resolve the competing claims, but many of the C.I.A.’s responses appear plausible on their face. At a minimum it is possible that the C.I.A.’s tactics did help it capture some very dangerous people planning future attacks.

That conclusion in turn casts doubt on the committee’s other main finding — namely, that the C.I.A. repeatedly lied about the program’s efficacy.

The C.I.A. admits that it should never have claimed “that the information it acquired could not have been obtained some other way.” Such assertions, it says, were “sincerely believed but were also inherently speculative.” But that is hardly a major concession. Anyone who thinks about it for a minute will realize that it is impossible to know whether information obtained in one way might not have been obtained in some other way. In retrospect, the Senate committee should not have given so much emphasis to whether torture works. The law does not prohibit torture because it is ineffective, but because it is wrong. As David Bromwich wrote in The London Review of Books, asking whether torture works is like asking whether slavery works. It’s the wrong question.

So why did the committee focus on efficacy and misrepresentation, rather than on the program’s fundamental illegality? Possibly because that meant it could cast the C.I.A. as solely responsible, a rogue agency. A focus on legality would have rightly held C.I.A. officials responsible for failing to say no — but it also would have implicated many more officials who were just as guilty, if not more so. Lawyers at the Justice Department wrote a series of highly implausible legal memos from 2002 to 2007, opining that waterboarding, sleep deprivation, confinement in coffinlike boxes, painful stress positions and slamming people into walls were not torture; were not cruel, inhuman or degrading; and did not violate the Geneva Conventions.

The same can be said for President George W. Bush, Vice President Dick Cheney and all the cabinet-level officials responsible for national security, each of whom signed off on a program that was patently illegal. The reality is, no one in a position of authority said no.

This may well explain the committee’s focus on the C.I.A. and its alleged misrepresentations. The inquiry began as a bipartisan effort, and there is no way that the Republican members would have agreed to an investigation that might have found fault with the entire leadership of the Bush administration.

But while the committee’s framing may be understandable as a political matter, it was a mistake as a matter of historical accuracy and of moral principle. The report is, to date, the closest thing to official accountability that we have. But by focusing on whether the program worked and whether the C.I.A. lied, the report was critically misleading. Responsibility for the program lies not with the C.I.A. alone, but also with everyone else, up to the highest levels of the White House, who said yes when law and morality plainly required them to say no.