WASHINGTON: The CIA does not give up its secrets easily. Even under public scrutiny and pressure from a Senate committee to declassify parts of a congressional report on harsh interrogations of suspected terrorists, the CIA remains shadowed by its reluctance to open up about its operations and its past.

In recent years, CIA decision-makers have wrestled with Congress, archivists, journalists, former CIA employees and even an ex-CIA director over which secrets could be revealed. Most often, secrecy prevails.

The CIA holds the upper hand, using its internal reviews of classified materials and a separate process to scan proposed books about intelligence practices to tightly guard what is known about its activities and its history. The CIA has used its sweeping national security authority to prevent embarrassing or damaging disclosures while shaping its own public image. “They’re tight-fisted by nature and the more they are pressed to disclose, the more they resist,” said Steven Aftergood, who studies government secrecy at the Federation of American Scientists in Washington.

The CIA’s own experts have begun a review of the Senate Intelligence Committee’s 400-page summary and findings on the CIA’s harsh interrogation techniques, according to government officials familiar with the process. CIA spokesman Dean Boyd said the agency, with help from other agencies, including the Pentagon and the departments of Justice and State, is carrying out an “expeditious classification review” of the Senate materials.

In referring the committee’s report to President Barack Obama earlier this month, the committee’s chairwoman, Democratic Senator Dianne Feinstein pointedly asked the White House and not the CIA to take the lead in declassifying the summary, which criticises the agency for its heavy use of the simulated drowning technique called waterboarding and other abusive interrogation methods against Al Qaeda suspects held in secret, agency-run prisons overseas.

Feinstein and CIA Director John Brennan have clashed over the handling of internal agency documents reviewed by the committee. But the White House, in a recent letter to Feinstein, committed only to having the director of national intelligence, James Clapper, oversee the CIA’s work.

The possibility that some CIA lawyers and officials who supported the agency’s use of harsh interrogation tactics might be involved in the Senate report’s declassification was a key reason Feinstein and some other senators pressed for strong White House involvement.

Former White House officials said Obama administration lawyers and national security officials likely will wait until after the CIA has finished most of its work before making recommendations or offering suggestions. “When it comes to declassification, the White House is very hands-off,” said Tommy Vietor, a former national security spokesman under Obama. “Intelligence professionals are the best ones to do that.”

The CIA has done it for decades, and sometimes it has taken them decades to finish the job. In 2011, the CIA declassified documents that described secret writing techniques — one involved lemon juice, a practice long known among adolescents — and a method for opening sealed letters without detection. Those documents were created in 1917 and 1918, and CIA took more than 10 years after outside researchers asked for them before it agreed to release them.

The CIA’s infamous Family Jewels, a trove of secret documents recounting covert and sometimes-illegal activities, including several botched assassination attempts on Fidel Castro, were kept under wraps for more than three decades until they were released during the Bush administration in November 2007.

The National Security Archive, a George Washington University programme that obtains declassified and historic intelligence and diplomatic files, had asked for them more than 15 years earlier.

“What we come up against repeatedly is the CIA’s knee-jerk assertion of national security,” said Thomas S. Blanton, the Archive’s director. “That comes down to one reality — the CIA’s desire to protect its own power and authority.”

CIA veterans who oversaw the handling of the agency’s secret files said critics have a simplistic view of the role the agency is obliged to play. “The CIA’s handling of declassification is judiciously done,” said John H. Hedley, a former CIA veteran who chaired the agency’s secretive Publications Review Board for three years in the late 1990s. Hedley’s board of experts came from across the agency and ruled on what could be printed in books written by former officials.

Publication review is distinct from declassifying historic records, but both processes are intended to tease out information for the public without compromising CIA sources and methods or hurting the agency’s relationships with foreign governments and intelligence services, Hedley said.

Boyd would not reveal the precise process or units that the CIA will use to declassify the Senate report, but CIA veterans say it’s likely that the agency’s information management specialists and its general counsel’s office will have key roles.

The agency often farms out some declassification decisions to experts in pertinent subject areas.

Democratic Senator Ron Wyden said he worries the CIA is playing “stall ball”, deliberately drawing out the declassification process.

He added that the agency’s history of “over-classification” has often been used to “protect their tailbones”.—AP