Hersh performed well, but struggled to understand the paper’s pathology, in which it was “a bitch” to get important stories into print. He quotes his former colleague Bill Kovach, later the Washington bureau chief, bemoaning the difficulty of “managing Sy at a newspaper that hated to be beaten but didn’t really want to be first. … The arguments and the debates and the rassling back and forth on every Sy Hersh story were almost endless. It wasn’t because Sy was sloppy. It was material they didn’t want to be out there with.”

For much of the time he felt supported: Hersh recognized in Rosenthal an editor with guts. But there were not infrequent screaming matches, temper tantrums, middle-of-the-night phone calls and accusations of betrayal. He was mortified in January 1975 to learn that top editors at the paper had enjoyed a private lunch with Gerald Ford in which the president had told of setting up a commission to investigate alleged C.I.A. abuses. Ford told the assembled editors that he needed to keep some things secret — “like assassinations.”

Hersh is appalled that this startling admission from a president should have been allowed to be off the record and — more than 40 years later — there is real bitterness in his rebuke: “Talk about unrequited love. The guys running my newspaper who for years had showered me with praise and raises had a higher loyalty to a president … than to someone who had pulled them out of the Watergate swamp.”

Hersh decamped to The New Yorker (where he had written before his stint at The Times), first under Tina Brown and then the “superb” David Remnick. Here he did much good work — but his habit of asking readers (and editors) to take on trust his heavy use of anonymous sources got him into scrapes. Many of his sources were — as time has shown — impeccably informed. But his more recent sources have also included, for instance, the Syrian president Bashar Assad. Some of his writing on who should bear responsibility for chemical weapon attacks in Syria has been vehemently contested.

Remnick — worried about his journalist’s reliance on “the same old tired source” — had already declined to use Hersh’s reporting that questioned the official narrative around the assassination of Osama bin Laden. Hersh is enraged — “editors get tired of difficult stories and difficult reporters” — and takes this and subsequent investigations off to The London Review of Books or to the German paper Die Welt.

It was painful for some to see Hersh’s 2014 and 2017 reporting of chemical attacks in Damascus forensically interrogated by the British blogger Eliot Higgins, who criticized his reliance on a tiny number of unnamed sources. Higgins is a new breed of reporter, encyclopedic in his knowledge of the weaponry deployed in this conflict, meticulously bolstered by video footage, as well as by multiple on-the-ground sources and satellite photographs.