The Senate intelligence committee report sparked a fierce political debate. Democrat senator Mark Udall said in a tweet that the report “corrects the record” on the CIA’s “brutal torture” program.

Republicans termed the ­account a partisan effort. Senator Dan Coats suggested in a tweet that the intelligence community shouldn’t fret, saying the report contains “no recommendations and offers only a partisan account of last decade’s counter-terrorism efforts.”

Michael Posner, a former State Department human rights official in Barack Obama’s first term, said the detailed accounts of physical and emotional abuse inflicted on prisoners by the CIA would have “longstanding consequences in terms of reinforcing the need for oversight of the intelligence agencies”.

The Obama administration sought to buoy an intelligence community whose prestige, reputation and morale were already dampened by the leaks from Snowden showing the National Security Agency was gathering US cellphone records on a widespread scale. “We recognise that every time there’s a difficult and painful chapter that is revealed in such a manner at this report, that can be challenging to the workforce,” said an administration official.

He said more Americans would have died in terrorist attacks over the past decade if it weren’t for the work of US intelligence agencies.

The report’s allegations were reminiscent of findings by a Senate committee led by Democrat Frank Church in the 70s that chronicled efforts by US agents to ­assassinate foreign leaders, open mail and spy on civil rights and anti-war ­activists.

A decade later, the Reagan ­administration was rocked by the Iran-Contra scandal, in which ­senior administration officials engineered a deal that traded arms to Iran in an effort to release US ­hostages, flouting law passed by congress.

Loch Johnson, an assistant to Church during the investigation, was confident the CIA could survive the acrimony stirred by the Senate report. He cited the intelligence community’s work in verifying arms control claims by other countries and providing battlefield assessments that help minimise US ­casualties in foreign conflicts.

“Keep in mind that 95 per cent of what the CIA is doing — and has done — is entirely legal and ­extremely valuable to the country,” he said. “The record of the CIA and these other agencies is quite outstanding. I hope we don’t paint the whole agency in dark tones just because of some ­episodes that occurred.”

Similar outrage erupted over the misdeeds disclosed by Church and in the Iran-Contra affair.

Leslie Gelb, president emeritus at the Council on Foreign Relations who served in the Johnson and Carter administrations, said he doubted the report would transform the way the CIA does business. Congress could try to bar the agency from torturing people or assassinating foreign leaders, but it won’t matter, he said.

“It will happen again,” he said. “It’s happened almost throughout their history. For a while, the CIA restrains itself and acts within the law. And after a period of years, we get the same things going on again.”