Munter demanded veto power over CIA drone strikes in Pakistan because the killing was out of control. But before he could finish, Leon Panetta, the CIA director, cut him off. “I don’t work for you,” he said.

Hillary Clinton, the secretary of state, began to defend Munter, turning to Panetta to tell him that the ambassador could not be steamrollered.

“No, Hillary,” Panetta responded, “it’s you who are flat wrong.”

Obama’s national security adviser, Tom Donilon, eventually brokered a supposed compromise. Munter could object to specific drone strikes but the CIA could then get approval from the White House. In effect the CIA had won — killing trumped diplomacy.

Munter resigned prematurely from his post and is on a three-year secondment to a Californian university. Admiral Dennis Blair, director of national intelligence and technically Panetta’s boss, was fired for criticising CIA operations.

At the end of his time at the CIA, Panetta, a staunch Catholic, joked: “I’ve said more Hail Marys in the last two years than I have in my whole life.”

Aside from the estimated number killed in Pakistan by American drones of up to 3,308, according to the New America Foundation, another casualty has been the CIA’s traditional mission of providing the president with intelligence about emerging threats and global developments. A senior Obama administration figure told Mazzetti: “The CIA missed Tunisia. They missed Egypt. They missed Libya.”