The first time Rex Tillerson met Donald Trump, the Texas oilman walked away with the job of secretary of state. It was all downhill after that.

In his 10 months as top diplomat for the world’s most powerful country, Mr. Tillerson has seen his mercurial boss undermine him on Twitter during the tense standoff over North Korea’s missile launches; publicly contradict him on a blockade of Qatar by other Middle Eastern countries; and disregard his advice on everything from the Paris Agreement on climate change to the Iran nuclear deal.

Things got so bad last summer that Mr. Tillerson reportedly referred to the U.S. President as a “moron” following a Pentagon meeting.

The man who spent a decade running Exxon Mobil, one of the world’s largest oil companies, has spent nearly his entire time in Washington facing rumours about his imminent ouster from office.

On Thursday, The New York Times, citing “senior administration officials,” reported the White House had a plan to dump Mr. Tillerson within the next few weeks and replace him with U.S. Central Intelligence Agency director Mike Pompeo. Asked about Mr. Tillerson at an unrelated Oval Office photo-op, the President did not deny he planned to axe him, replying only: “He’s here. Rex is here.”

If Mr. Tillerson soon finds himself shown the door, it will cap an unprecedented period in U.S. foreign policy, in which the Secretary of State found himself regularly presenting a completely different message to the world than the President he serves. Mr. Tillerson has repeatedly tried to steer the administration closer to the mainstream of global foreign policy, only for Mr. Trump to intervene and pull it back to the fringes.

“It’s dangerous for a secretary of state to have so little credibility [when] speaking on behalf of the President and the U.S. government, whether it’s in diplomacy with our allies or our adversaries,” Matthew Waxman, a former senior official at the State and Defence departments during the George W. Bush administration, wrote in an e-mail. “It could lead to misunderstanding and escalation of a crisis; it could undermine confidence in assurances or threats by the Secretary of State; during a crisis it could lead other governments to discount what the Secretary of State says, and it could create confusion within the U.S. government.”

In September, after Mr. Trump and North Korean dictator Kim Jong-un traded threats of nuclear annihilation, Mr. Tillerson tried to de-escalate by offering to talk to Pyongyang. But the President swiftly smacked him down. “Save your energy Rex, we’ll do what has to be done!” he tweeted.

In the spring, as Mr. Tillerson sought to mediate between Qatar and its regional rivals, Mr. Trump declared the blockade “necessary” because Doha was a “funder of terrorism at a very high level.”

And the pair regularly sing from different song sheets on international obligations: Mr. Tillerson says the United States will stay in the Iran deal (Mr. Trump has toyed with leaving it); might not withdraw from the Paris Agreement (Mr. Trump has said he will); and will stand by its long-time commitment to defend NATO allies in the event of invasion (Mr. Trump has often been ambivalent).

Jordan Tama, a foreign-policy expert at American University in Washington, said disagreements have historically arisen between the State Department and the White House from time to time: Hillary Clinton and John Kerry, for instance, favoured more intervention in Syria than Barack Obama did; William Rogers, Richard Nixon’s first secretary of state, was largely cut out of Henry Kissinger’s planning for the opening to China. But the public nature of the current discord is unique.

“It’s very problematic to conduct diplomacy with foreign leaders when the foreign leaders can’t trust that what Tillerson tells them isn’t going to be reversed,” Prof. Tama said.

Mr. Tillerson is hardly the only figure in Trumpworld to try to moderate the President’s impulses – Secretary of Defence James Mattis, Ambassador to the UN Nikki Haley and chief of staff John Kelly have all done so to varying degrees – but Mr. Tillerson appears to have raised Mr. Trump’s ire in a way the others haven’t.

Prof. Tama suggests this might have to do with Mr. Tillerson’s lack of a constituency of his own: While Mr. Mattis is a career soldier who commands respect within the Pentagon and Ms. Haley is seen as a prospective future president by the GOP establishment, Mr. Tillerson doesn’t have a power base in the government.

It likely also doesn’t help that Mr. Tillerson’s attempts to overhaul his department appear to have fallen flat: Career diplomats have long complained he is ignoring their advice or giving them nothing to do, while trying to run every file with a small circle of insiders.

Prof. Waxman, who now teaches at Columbia University’s law school, said Mr. Tillerson’s instinct to reform the bureaucracy is correct, but that he appears to have irreparably “botched” the process.

“I’ve never seen morale so low at the State Department and there’s a tragic drain of talent going on that will be hard to remedy,” he said.

In an interview with the Independent Review Journal last March, the Secretary of State revealed he had never met Mr. Trump before the election. During the transition period, the president-elect summoned Mr. Tillerson to Trump Tower to ask him about global affairs. At the end of the chat, Mr. Trump stunned Mr. Tillerson by asking him to join his cabinet.

“I didn’t want this job. I didn’t seek this job,” Mr. Tillerson told the IRJ. “My wife told me I’m supposed to do this.”

The Globe and Mail, November 30, 2017