Rex Tillerson’s team was fighting again. “So, who’s going to go in with him?” Margaret Peterlin, his chief of staff, was saying. She looked me up and down with an expression that suggested she’d discovered a pest in the house. We were standing at the wide double doors into the Secretary of State’s office on Mahogany Row, the opulent, wood-panelled corridor on the seventh floor of the State Department’s Washington, D.C., headquarters, which houses the most powerful offices in American foreign policy. Steven Goldstein, the Under-Secretary of State for Public Diplomacy and Public Affairs, folded his arms and stared daggers at Peterlin. “Well, I guess I won’t be,” he told her. “Heather can go.” Goldstein tilted his head toward Tillerson’s spokesperson, the former Fox News anchor Heather Nauert. Peterlin narrowed her eyes at Goldstein. “Are you sure?” she said, with theatrical displeasure. Goldstein didn’t reply. Tillerson strode up to the door, cutting the tension. Nauert and Peterlin joined the interview, along with Tillerson’s director of policy planning, Brian Hook. Goldstein remained outside. (Peterlin said that she was following a rule enacted by Secretary Tillerson that only one communications officer be allowed in his interviews.)

Such discord often simmered just under the surface in the year before Tillerson’s unceremonious firing, in March, according to multiple members of his embattled inner circle. Often, it emanated from Peterlin, a formidable attorney, U.S. Navy veteran, and former congressional staffer who helped draft the Patriot Act after the September 11th attacks and guided Tillerson through his confirmation process. When she was passed a note indicating I’d arrived that day, she’d given the rest of the team an ultimatum: from the public-relations staff, only Goldstein would be permitted in the interview. Goldstein had pointed out that Nauert, as spokesperson, would be responsible for answering ensuing public questions. Peterlin insisted that there was simply no room. One staffer present said that there was another motivation: Peterlin had been lobbying to get Nauert fired. (Peterlin said that she did not lobby to fire Nauert, and pointed out that Nauert still holds her position as spokesperson today.) The standoff hadn’t been resolved by the time I was ushered in to see Tillerson, nor as I left, when a second contretemps erupted over who would stay behind with the Secretary. (Goldstein again insisted on Nauert, visibly vexing Peterlin.) This squabbling barely qualified as drama, but displaying it so openly in front of a reporter was at odds with the kind of tightly organized messaging prized by most of Tillerson’s predecessors. It provided a small window into a State Department that appeared to be plunged into chaos at every level.

In that meeting, in January, Tillerson was wearing a charcoal suit and a canary-yellow tie, patterned with horseshoes. He was sitting, legs crossed, in one of the blue-and-gold upholstered chairs in the Secretary’s office. Tillerson had redecorated, replacing the portraits of dead diplomats with scenes of the American West. He got compared to a cowboy a lot, and, between the décor and the horseshoes, he appeared to be leaning into it. The name helped: Rex Wayne Tillerson, after Rex Allen and John Wayne, the actors behind some of Hollywood’s most indelible swaggering cowboys.

Tillerson was born in Wichita Falls, Texas, and was raised there and in neighboring Oklahoma, by parents of modest means. His parents met through the Boy Scouts, when his mother visited her brother at the camp where Tillerson’s father worked. Tillerson honored that legacy by remaining active in Boy Scouts leadership for much of his career. His biography is marked by earnest overachievement: he was an Eagle Scout, and then a member of his high-school band, in which he played the kettle and snare drums, and which yielded a marching-band scholarship to the University of Texas at Austin. In the course of more than forty years at ExxonMobil, culminating in his decade-long tenure as the company’s C.E.O., he amassed a personal fortune of at least three hundred million dollars—not including the roughly hundred-and-eighty-million-dollar retirement package he received when he departed the firm to enter government. The call to serve in the Trump Administration had thrown into disarray his plans for retirement, which he had intended to spend with his wife, Renda, on their two horse and cattle ranches in Texas. When I asked if, a year in, he thought he'd made the right call taking the job, he laughed. Peterlin shot him a warning look. “Yeah,” he said. “It’s been” —he furrowed his brow, appearing to search for the word— “interesting.”

When President Trump nominated Tillerson to be the Secretary of State, his experience running one of the largest corporations in the world inspired optimism among career officials. Maybe, several said, he’d bring to the job a private-sector knack for institutional growth—or at least savvy, targeted trimming. “Things were blue skies” when Tillerson was nominated, Erin Clancy, a foreign-service officer, recalled. “His business record was promising.”

But the problems mounted quickly. Gossip began to make the rounds in D.C., portraying Tillerson as aloof and insulated from the Department. After brief remarks on his first day, he didn’t speak to the workforce again until a town hall in May of last year, unusually late into the Administration for a new Secretary of State. Another time, he gave employees an overview of the basics of world conflicts. Some found it condescending. “It was an exercise in ‘I can read a map,’ ” one foreign-service officer in attendance recalled. When Tillerson then told a story about attending a Model U.N. session and telling a twelve-year-old participant how much the Foreign Service inspired him, a middle-aged officer audibly muttered, “You don’t fucking know us.”

Several staffers said Tillerson’s inaccessibility extended to his foreign counterparts. “He is not a proactive seeker of conversations,” an officer in the State Department’s Operations Center, who spent months connecting Tillerson’s calls, told me. When new Secretaries are sworn in, they typically receive a flood of courtesy calls from foreign ministers. More than sixty came into the Operations Center for Tillerson. He declined to take more than three a day. In April of last year, when the United States initiated strikes on Syria, the Administration skipped the conventional step of notifying its NATO allies. “When news broke, alarmed allies . . . were calling” the operations officer told me. It was early on a Sunday afternoon, and Tillerson was in Washington and unoccupied. “We were told that the Secretary had a long weekend, so he was going to go home and have dinner with his wife and call it a night.” No calls. “That floored me,” the operations officer recalled.

One source close to the White House struggled to reconcile Tillerson’s peerless track record of private-sector management with his approach at the State Department. “Forty years at Exxon, in the God Pod, telling people to jump based on how high the price of oil is up,” the source said, using the pet term for Tillerson’s office suite within ExxonMobil. “I’m not trying to be shitty, but, you know, there’s a way to run that company.” Government, where no man is God (except the President), was something else. “At first, I thought, Uh-oh, this is growing pains; a private-sector guy, realizing how hard Washington is,” the source close to the White House continued. “And just, what I started to see, week after week, month after month, was someone who not only didn’t get it but there was just no self-reflection, only self-mutilation.”