Evan Thomas is the author of “Being Nixon: A Man Divided.”

In 1974, Bob Woodward, together with his fellow Washington Post reporter Carl Bernstein, published “All the President’s Men,” about their role in exposing the Watergate scandal. Woodward has gone on to write 11 other No. 1 bestsellers and establish himself as the best reporter in town at getting top government officials to spill their secrets. The Woodward method is legendary: flattery, patience and relentless persistence.

In 2011, Woodward invited Alexander Butterfield, the deputy assistant to President Richard Nixon who revealed the existence of the White House taping system during the 1972 Watergate hearings, to the weekend home he and his wife, Elsa Walsh, keep on the South River, near Annapolis. Three years later, Butterfield sat down for 40 hours of interviews with Woodward and turned over more than 20 boxes of documents, some of them highly secret, that he had carried away from the White House in 1973.

“The Last of the President’s Men” is the catchy title of Woodward’s latest book, but, notably, Butterfield was not one of the president’s men, in the sense that he was never a member of the palace guard of Nixon loyalists. Woodward makes much of a previously undisclosed January 1972 memo, provided by Butterfield, that shows Nixon angrily writing that U.S. bombing had achieved “zilch” in Vietnam. The document is interesting but not surprising. Nixon was a blurter: On the White House tapes you can hear him repeatedly railing about the futility of the U.S. Air Force. Woodward’s book contains no real bombshells, but it does offer a cringe-worthy portrayal of the 37th president, seen through the eyes of an aide who sometimes witnessed the better side of Nixon but more often, in Woodward’s telling, the worse.

Although Butterfield handled the president’s day-to-day logistics and much of his paperwork, he was always a bit of an outsider. He held himself aloof from the hyper-efficient aides and advancemen from Nixon’s political campaigns. When Butterfield testified against the president before the House Judiciary Committee during the 1974 impeachment hearings, Rose Mary Woods, Nixon’s devoted secretary, harangued him over the phone. “You’re on the other side,” she said. “You always were.”

‘The Last of the President's Men’ by Bob Woodward (Simon & Schuster)

It has been speculated that Butterfield was a plant for the CIA or the Pentagon intent on spying on Nixon. The conspiracy theories have never been proved, and Butterfield told Woodward the more plausible story that he was just an ambitious young man who wanted a White House job. A UCLA classmate of Nixon’s chief of staff, H.R. “Bob” Haldeman (their wives had been sorority sisters), Butterfield was handsome, brave (he had flown 98 missions in Vietnam) and knew how to keep a clean desk. Haldeman hired him to be his “staff clone,” Butterfield told Woodward — a carbon copy of the chief of staff, ready to step in and do whatever Nixon wanted.

There was just one problem, Haldeman explained to his new aide, a bit awkwardly, when Butterfield reported for duty in January 1969. Nixon was uncomfortable with strangers. Haldeman tried to keep Butterfield out of sight of the president for his first two weeks on the job. When the chief of staff finally introduced his deputy to the president, Nixon was literally speechless. As Woodward renders the scene:

“ ‘Ah, uh, hmm, ah, ahh,’ the president mumbled, clearing his throat and gesturing toward Haldeman. ‘Urm, urm.’ His right hand went up to his mouth, covering it briefly. He seemed about to speak, glanced at Butterfield and motioned to Haldeman. But still there were no words. Nixon began to make little circles with his hand as if to recall something to mind. ‘Urm, urm,’ he said.”

Butterfield has told this story in a 2008 oral history publicly available at the Nixon Library, but Woodward tells it more entertainingly — and harshly. To be sure, Nixon could be helplessly awkward in social company, but he also could be cool and commanding, especially when negotiating with heads of state. He was able to get along with Leonid Brezhnev and Zhou Enlai because he did not preach at them, he was well-prepared and he discussed interests, not ideology. He also got on fine with plenty of politicians and regular people, including, on one memorable occasion, Elvis Presley, his fellow anti-establishmentarian.

Woodward puts Nixon’s pettiness on vivid display. On Christmas Eve of his first year in office, Nixon spends 18 minutes walking around the White House to wish his employees a Merry Christmas. Woodward writes: “He found something very disturbing. A number of the offices prominently displayed pictures of the late president John F. Kennedy. I want all those pictures down today, Nixon ordered Butterfield. ‘Down from the walls and off the desks. Jesus Christ! If we’ve got this kind of infestation imagine what [Secretary of State] Bill Rogers has at the State Department.’ ”

Butterfield describes to Woodward a pathetic moment aboard Marine One, the presidential helicopter. In the semi-darkness, Nixon awkwardly pats the bare leg of a mini-skirted secretary, Beverly Kaye; she stiffens but says nothing. “I just thought, the poor, pitiful son of a bitch,” Butterfield tells Woodward. In later conversation with Woodward, Butterfield describes the patting as grandfatherly, but Woodward milks it for several pages.

Butterfield does find some attributes to admire in Nixon: “the work ethic, snatches of empathy, the determined, focused effort so evident in nearly everything he did.” But the president’s deputy assistant is grudging and misses some crucial dimensions of his infinitely complex and contradictory boss. Butterfield offers a scene of Nixon ignoring his wife, Pat, and describes the first lady as “borderline abused.” Nixon, it’s true, could be embarrassingly dismissive of Pat in public. But over a long and complicated marriage, he also showed tenderness and depended on her, almost desperately, to stand by him in difficult times. Anyone who questions the depth of Nixon’s devotion needs only to Google the video of Pat Nixon’s funeral. Nixon is not just crying; he is bawling, devastated, utterly undone. He was dead a year later.

In some ways, Woodward’s portrait of Butterfield is more intriguing than Butterfield’s portrait of Nixon. Why did Butterfield reveal the existence of Nixon’s secret taping system to Senate investigators probing Watergate? Because he was asked, is the simple answer, but Woodward understands that Butterfield’s motivations were more complex. He quotes the spy novelist John le Carre’s 1979 thriller, “Smiley’s People,” about the floor at headquarters where the bosses had their offices: “Why did the fifth floor always think that people had to have one motive only?” Woodward notes that Butterfield, a former Eagle Scout who carried the cross in church as an altar boy, was resentful that Nixon had pressured him into using the Secret Service to spy on Sen. Edward M. Kennedy (D-Mass.). Possibly, Butterfield felt guilty that he had not refused to be used in this way.

“I had come to like him,” Butterfield says of Nixon in one of his interviews with Woodward, who described Butterfield’s almost tortured feelings toward his former boss: “‘We had tacitly kissed and made up,’ from the early days in 1969. ‘But he was rude to me. He was clearly rude, but I softened.’ Still, Butterfield always remembered. ‘Two or three times he was rude to me,’ he recalled, his eyes narrowing as he thought back. There had never been an apology. . . . Butterfield took snubs very personally, and by his own account they tended to almost live within him for years, even decades afterward.”

Nixon could be considerate with his aides. Butterfield describes a sweet scene of Nixon meeting with Butterfield’s teenage daughter, who had lost her teeth in a car crash. Nixon empathetically tapped his own front teeth, capped after they had been broken in an accident. He also could be callous. In their own memoirs, Haldeman recalled that Nixon never made an effort to learn about his children, while his other top aide, John Ehrlichman, wrote that Nixon sometimes distractedly called him “Bob.” Nixon was at heart a lonely man. He paid for it.

The Last of the President’s Men

By Bob Woodward

Simon & Schuster. 291 pp. $28