Rex Tillerson’s disastrous tenure as secretary of state may finally be coming to an end.

The New York Times reports that the White House is planning to fire Tillerson and replace him with current CIA Director Mike Pompeo sometime in the next few weeks.

This wouldn’t necessarily be a bad thing. The consensus among foreign policy observers is that Tillerson’s time as secretary of state has been an unmitigated disaster.

“Tillerson would be at or near the bottom of the list of secretaries of state, not just in the post-Second World War world but in the record of US secretaries of state,” says Paul Musgrave, a scholar of US foreign policy at the University of Massachusetts Amherst.

The former Exxon Mobil CEO — whose nomination was initially greeted warmly by prominent foreign policy hands — has failed to wield any significant influence in internal administration debates over issues like Syria, North Korea, or Russia.

His push to slash “inefficiencies” in the State Department and seeming disinterest in working closely with longtime staff were even more damaging. By failing to get people into vital high-level posts and actively pushing out talented personnel, he ended up making America’s response to major crises incoherent and weakening the State Department for a “generation,” according to George Washington University’s Elizabeth Saunders.

This can’t all be blamed on Tillerson: Even a skilled and experienced diplomat would have had trouble maintaining influence in the chaotic Trump White House, where people like UN Ambassador Nikki Haley and Jared Kushner wield major influence and foreign policy is often made by tweet.

Yet both nonpartisan experts and high-ranking State Department appointees in the past two administrations believe he personally deserves much of the blame.

"I think he really will go down as one of the worst secretaries of State we've had," Eliot Cohen, counselor to the State Department under President George W. Bush, told Axios’s Jonathan Swan. “He will go down as the worst secretary of state in history,” tweeted Ilan Goldenberg, an Obama-era official who worked on Israel-Palestine issues.

Tillerson was expected by many to be one of the “adults in the room,” helping Secretary of Defense James Mattis rein in some of Trump’s most wild ideas. His attempts to play that role backfired, and his ham-handed attempts to manage Trump alienated the president, who has reportedly complained about Tillerson’s “totally establishment” views on foreign policy.

Combining the lack of influence over Trump with his single-minded, personal pursuit of State Department “reform” — which really amounted to gutting the department and forcing out longtime employees — you have a truly disastrous tenure in Foggy Bottom.

“He took the job and made it smaller,” Musgrave says.

Tillerson failed at the thing he was supposed to be good at

When Trump announced Tillerson as his pick for secretary of state back in December 2016, the foreign policy community was of two minds on the appointment.

As CEO of Exxon Mobil, one of the world’s largest corporations, Tillerson seemed to be more than qualified to effectively manage a sprawling bureaucracy like the State Department. Mainstream GOP foreign policy experts like former Defense Secretary Robert Gates, former Secretary of State Condoleezza Rice, and former National Security Adviser Stephen Hadley all praised the pick.

"He would bring to the position vast knowledge, experience, and success in dealing with dozens of governments and leaders in every corner of the world,” Gates said in a statement. "He is a person of great integrity whose only goal in office would be to protect and advance the interests of the United States.”

Critics, though, worried about Tillerson’s close relationship with Vladimir Putin, and about Exxon’s willingness to strike deals with corrupt foreign dictators and history of lobbying against action climate change (though the corporation now says it accepts climate science). During Tillerson’s January confirmation hearings, senators grilled him about both Russia and climate, with Democrats clearly unsatisfied by his answers.

"Do you lack the knowledge to answer my question or refuse to answer my question?" Sen. Tim Kaine (D-VA) puffed, after Tillerson repeatedly stonewalled his questions about Exxon funding climate change denial. "A little of both,” Tillerson replied.

Tillerson was confirmed in late January nonetheless, in a vote that basically fell along party lines. Quickly, he set about upending everyone’s views about him. As early as March, it had become clear that the conventional wisdom was 100 percent wrong. The fears about Tillerson’s policy views had proven overblown, mostly because he had been completely overshadowed in internal White House deliberations over issues like Syria and Russia.

“More than a month after he became America’s top diplomat, Rex Tillerson is like no other modern secretary of State: he’s largely invisible,” the LA Times’s Tracy Wilkinson reported at the time. “His influence at the White House is difficult to discern. He appears to be competing with Jared Kushner, Trump’s son-in-law, and Stephen Bannon, the president’s chief strategist, both of whom have Trump’s ear on foreign policy.”

The optimism about Tillerson’s management acumen, by contrast, had clearly been badly misplaced. Tillerson failed to fill a number of vital leadership positions, spent almost no time interacting with his own employees, and pushed out long-serving career professionals without clear replacements in mind. Morale inside the organization collapsed.

“I used to love my job,” one staffer told the Atlantic’s Julia Ioffe at the time. “Now, it feels like coming to the hospital to take care of a terminally ill family member. You come in every day, you bring flowers, you brush their hair, paint their nails, even though you know there’s no point. But you do it out of love.”

What was true in March remained true for the rest of Tillerson’s time in office to date. On issue after issue, Tillerson proved to be out of touch with the president’s foreign policy positions. The US bombed Syrian dictator Bashar al-Assad in early April — just days after Tillerson suggested the administration would be fine with Assad staying in power. On June 9, Tillerson called on Saudi Arabia and its allies to end their isolation of Qatar; less than two hours later, Trump sided with the Saudis by labeling Qatar “a funder of terrorism at a very high level.”

The staffing problem at the State Department has gotten worse as time has gone on. By mid-September, only 24 of 148 political appointees had confirmed by the Senate, according to a count by the Washington Post and the Partnership for Public Service. Tillerson had not nominated anyone to be the assistant secretary supervising vital regions like Asia and the Middle East, nor had he nominated ambassadors for countries as important as Saudi Arabia and South Korea.

This kind of vacancy is devastating.

Political appointees are necessary to shape policy, as they serve as a conduit between the administration and foreign governments. Without people in these positions, career diplomats fill in as best they can, but they have a hard time making new decisions or formulating new policy. It’s nigh unprecedented to go this long with this many vacancies because it cripples America’s ability to develop diplomatic stances on vital issues.

And it’s not like this was a quiet time for foreign policy. During Tillerson’s tenure, North Korea has tested both a ballistic missile that could theoretically hit Washington and its largest nuclear device ever. One US ally in the Gulf (Saudi Arabia) laid economic siege to another (Qatar). And the US bombed Bashar al-Assad in Syria for the first time.

Even the career staff has suffered under Tillerson. He eliminated entire segments of the department, like the department that tracked war crimes. He imposed limits on transfers inside the organization, typically a way the State Department deals with staffing shortages, in late June. He cut off the department from vital recruiting sources, like the Presidential Management Fellow program. He publicly defended a Trump administration proposal to cut his department’s budget by 30 percent, and devised a plan to cut the permanent staff by 8 percent.

He attempted to defend these ideas in a September meeting with members of Congress by use of a PowerPoint presentation outlining his vision for the department — which he could theoretically use to say he finished his reorganization plan and can now hand it over to others to carry out. The slides are chock-full of management jargon. In one section, titled “Description of Redesign Workstreams,” Tillerson promised to “identify ways to promote an agile and empowered workforce as part of an overarching talent map.”

This presentation did not persuade Congress, which has repeatedly rebuffed Tillerson’s requests to cut State’s budget. But it is emblematic of Tillerson’s style, in a way that shows how he managed to alienate his own employees so thoroughly.

“Secretary Tillerson’s term has led to widespread demoralization in the foreign service, the dismissal or resignation of people with expertise that individually may not be irreplaceable but as a cohort certainly becomes so,” Musgrave says. “That hinders the State Department’s ability to enhance US interests through diplomacy.”

The consequences may not be visible immediately. But State’s personnel shortages could prevent the United States from successfully reaching a diplomatic solution to issues in everything ranging from the South China Sea to the Israeli-Palestinian conflict. You can’t negotiate very well if you don’t have people who know how to do it — and the more people the State Department loses, the longer-term the consequences of these problems are, as there’s no one to promote to senior roles.

Saunders analogizes the US under Tillerson’s emaciated State Department to a person who doesn’t have health insurance. “Your life is probably fine — up until the point you get sick,” she says.

The sources of Tillerson’s failures are both Trump and Tillerson’s own choices

Why did things go so wrong for Tillerson?

Some of the blame has to be laid at his boss’s feet. Trump is running a chaotic administration that has nominated a shockingly low number of political appointees across practically every department. The White House shot down so many of Tillerson’s picks for top deputies that he actually screamed at a group of White House aides during a late June meeting out of frustration.

Trump personally displayed little to no interest in learning from the expertise of State Department personnel, preferring instead to delegate foreign policy to Kushner and occasionally announce policy shifts via tweet.

“It may be that in a Trump administration, the structural realities of the way the White House works [mean] you can only choose among varieties of failure,” Musgrave says.

But that excuse only goes so far. Secretary of Defense Mattis hasn’t been immune to Trump’s bizarre management style, either — he was blindsided, most notably, by Trump’s proposal to ban transgender people from serving in the military. But on the whole, Mattis has been far more effective at advocating for his department’s interests and gaining influence over the president’s decision-making than Tillerson.

That’s partly because Trump has more respect for generals than diplomats. Another part of it is that Mattis seems better at handling Trump’s mercurial nature; according to the New York Times, Tillerson frequently annoyed the president in meetings by (among other things) saying “It’s your deal” whenever Trump overruled him.

But a third and vital part of it, experts say, is that Mattis — a career military professional and former general — is substantially better at working in Washington. In particular, Mattis understands that working closely with his staff in the Pentagon allows him to advance policy ideas through the bureaucracy.

“Mattis is drawing on the expertise of his building. Some of that is a product of [his own] experience,” Saunders says. “Tillerson is not a creature of his building, nor is he a creature of government at all.”

By most accounts, Tillerson failed to build relationships with people in Foggy Bottom, relying instead on an insular inner circle made up of a few longtime confidants. This decision “constitutes the core of his failure,” according to Musgrave: It made it hard for Tillerson to garner influence inside the White House and to understand what his staff could do and how to deploy them effectively.

“Tillerson had a half-dozen, maybe a dozen, aides who are not familiar with Washington and especially not familiar with the State Department,” Musgrave says. “But he seems to rely on these people who are loyal to him, known to him, at the expense of building relationships with the people in the building.”

Perhaps if Tillerson had developed closer relationships with State’s career staff, he would have understood that supporting budget cuts to his own department and staff downsizing would demoralize them. Perhaps he would have been able to develop new ideas that would have gotten the president’s ear. Perhaps he would have been more able to convince the White House to trust his judgment on political appointees.

Perhaps, perhaps, perhaps. But the truth is we won’t know because Tillerson, to a degree nearly unprecedented in State’s history, failed to even try to work with his own department — turning his term into both a tragedy and a farce.

This raises an obvious, if strange, question: Why did this multimillionaire leave his cushy job at the head of one of the world’s largest corporations to lead a government bureaucracy he didn’t understand and seemingly didn’t respect?

It’s a question only Tillerson can answer.