The U.S. and NATO ceremonially ended their combat mission in Afghanistan on Monday, 13 years after the Sept. 11 terror attacks sparked their invasion of the country to topple the Taliban-led government.

NATO's International Security Assistance Force Joint Command, which was in charge of combat operations, lowered its flag, formally ending its deployment. U.S. Gen. John F. Campbell, commander of NATO and U.S. forces, said that the mission now would transition to a training and support role for Afghanistan's own security forces. From Jan. 1, the coalition will maintain a force of 13,000 troops in Afghanistan, down from a peak around 140,000 in 2011.

As the US prepares for the publication of a report examining the CIA’s use of torture after 9/11, the UK is among several close allies thought to be concerned that it will shed new and disturbing light on their role in the so-called rendition programme.

After a six-year examination of CIA documents, the Senate intelligence committee will on Tuesday release a 480-page summary of its 6,200-page report on the way in which the agency mistreated al-Qaida suspects held in secret prisons in Europe, Asia and the Middle East.

One highly detailed but unofficial investigation concluded last year that the programme was assisted by 54 countries worldwide, 25 of them in Europe.

The summary of the Senate committee’s report has been redacted in consultation with the CIA, but according to recent media reports, the committee chair, Dianne Feinstein, has won a victory by retaining within it significant amounts of information about the activities of US allies. While those countries’ roles are expected to be detailed, they are expected to be anonymised.

The UK government, which has never permitted an effective domestic inquiry into its involvement in the CIA’s global kidnap and torture operation to run its full course, appears to have good reason to be concerned about some of the material that may lie within the committee’s report.

In 2004, for example, MI6 engaged in at least two rendition operations alongside the CIA, resulting in a pair of Libyan dissidents being abducted with their wives and children, aged between six and 12, and flown to Muammar Gaddafi’s prisons. One of the wives, who was pregnant, says she was bound head-to-foot with tape to a stretcher for the 17-hour flight.

Furthermore, British intelligence officers interrogated detainees held at Guantánamo Bay and at Bagram in Afghanistan, despite being aware they were being mistreated, and the UK government provided logistical support for aircraft in rendition operations, allowing them to refuel at British civilian and military airports on hundreds of occasions.

At least two detainees were flown via Diego Garcia, which is British territory.

The full extent of the UK’s involvement in the rendition programme remains unclear however. Last year, the government shelved an official inquiry, but not before the judge in charge said that there were 27 areas in which questions about the UK’s involvement in rendition and mistreatment of detainees remained unanswered.

WASHINGTON — Former Vice President Dick Cheney offered a full-throated defense of the Central Intelligence Agency on Monday, arguing that its harsh interrogations of terrorism suspects a decade ago were “absolutely, totally justified” and dismissing a new Senate report criticizing them.

Mr. Cheney, who was a vocal champion of those techniques after the attacks of Sept. 11, 2001, and has never accepted the widespread description of them as torture, said he had not read the report that the Intelligence Committee is expected to release on Tuesday. But from news reports about it, he said he had heard nothing to change his mind about the wisdom and effectiveness of the program.

“What I keep hearing out there is they portray this as a rogue operation and the agency was way out of bounds and then they lied about it,” he said in a telephone interview. “I think that’s all a bunch of hooey. The program was authorized. The agency did not want to proceed without authorization, and it was also reviewed legally by the Justice Department before they undertook the program.”

Mr. Cheney said he never thought the C.I.A. was withholding information from him or the White House about the nature of the program, nor did he think the agency exaggerated the value of the intelligence gained from waterboarding and other techniques. The reported conclusion by the Senate Intelligence Committee that the C.I.A. misled the White House, he added, “is just a crock.”

“They deserve a lot of praise,” Mr. Cheney said. “As far as I’m concerned, they ought to be decorated, not criticized.”

He said critics had forgotten that the purpose was to prevent another Sept. 11. “When we had that program in place, we kept the country safe from any more mass casualty attacks, which was our objective,” he said.

The program, he added, was “the right thing to do, and if I had to do it over again, I would do it.”