Dianne Feinstein, the chair of the Senate’s Intelligence Committee, has lashed out against the CIA in a 45-minute speech that took fellow senators by surprise.

The senator accused the agency of withholding information about the treatment of prisoners, deleting some 900 pages from computers the committee was using and urging the FBI to bring charges against it for the “crime” of finding incriminating CIA documents that the CIA said were to be kept secret from the committee for reasons of “national security”.

Feinstein has otherwise been a vociferous defender of the vast spying operations of the NSA. She has publicly called Edward Snowden a traitor and demanded that he be captured and brought to trial under the witch-hunting Espionage Act.

Her conflict with the CIA concerns a more narrowly drawn issue – the agency’s detention policies under the administration of George W. Bush. Those included the widespread use of torture, secret prisons, indefinite imprisonment of people without charge and “special rendition” of some prisoners to Assad’s Syria, Mubarak’s Egypt and elsewhere for more extreme forms of torture.

More than a year ago, the Intelligence Committee completed a report on those activities. The CIA has blocked its release.

The New York Times editorialised, “It was outrageous enough when two successive presidents [Bush and Obama] papered over the Central Intelligence Agency’s history of illegal detention, rendition, torture and fruitless harsh interrogation of terrorism suspects.

 “Now … [Feinstein] has provided stark and convincing evidence that the CIA may have committed crimes to prevent the exposure of interrogations that she said were ‘far different and far more harsh’ than anything the agency had described to Congress.”

Feinstein said that an internal review by the CIA’s own inspector general came to the same conclusions as the committee’s staff report. It was the committee’s discovery of this internal review that the CIA said was a crime.

The CIA’s attorney, Robert Eatinger, was previously a lawyer for the CIA’s Counter Terrorism Center – the section that was running the detention and torture program. He was one of two lawyers whose advice led to the 2005 destruction of videotapes of brutal interrogations of prisoners by the CIA.

It wasn’t until 2007 that the CIA’s destruction of those videotapes became known. That was the reason the Senate Intelligence Committee began its investigation, culminating years later in its report.

The committee found that the CIA lied when it said that the torture produced useful intelligence, which was also the conclusion of the internal CIA report, according to Feinstein.

Feinstein strongly suggested that the CIA’s obstruction of the committee’s report was a violation of the separation of powers under the US Constitution and of the Fourth Amendment in the Bill of Rights.

The Fourth Amendment states: “The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”

We are left with the spectacle of Feinstein approving the violation of the Fourth Amendment rights of every US citizen by the NSA, while denouncing the CIA when it comes to her rights.

Feinstein is a leading Democrat. Her charges against the CIA reflect a rift in the party. Senate leader Harry Reid, also a Democrat, has entered the fray on Feinstein’s side, opening an investigation into what he called the CIA’s “absurd claims” that the committee’s staff had hacked into the agency’s network.

The rift also pits these Democrats against the Democratic White House, which is responsible for the CIA.

The Times editorial noted, “The lingering fog about the CIA detentions is a result of Mr Obama’s decision when he took office to conduct no investigation of them.”

An editorial in the British Financial Times elaborated: “On reaching office, US president Barack Obama said ‘we need to look forward not backwards’ on the Bush administration’s torture program. As a result, there have been no prosecutions on his watch. But the past keeps reaching out to grab him.”

Obama reacted to Feinstein’s charges by reluctantly “urging” that the Intelligence Committee’s report be declassified and published. He could declassify it immediately himself, but he wants the CIA to have more time to censor the most damning parts of it.

At the same time, the White House is protecting the CIA from the very serious charges Feinstein has levelled. Eric Holder, the attorney general, has ruled out any investigation of Feinstein’s charges.

The likely upshot is that some version of the report will eventually be declassified, no doubt censored. But no prosecutions of CIA or Bush administration officials will ensue. The issue will be declared “over”, and the administration will once again “look forward not backwards”.

Just as is happening with the NSA revelations, the massive national security state will remain intact, if discredited.