The sudden firing on Tuesday of Secretary of State Rex W. Tillerson, the former Exxon Mobil chief executive who never managed to capture the role of chief diplomat, makes room for a true believer in President Trump’s “America First” views and a bitter critic of the Iran nuclear deal — but also a deep skeptic about whether negotiations will convince North Korea to abandon its nuclear arsenal.
Mr. Tillerson’s anticipated replacement, C.I.A. director Mike Pompeo, was among the harshest of critics of the 2015 nuclear agreement that world powers brokered with Iran. If confirmed, Mr. Pompeo would take over the State Department just as the president is weighing whether to ditch the deal altogether — even if it outrages European allies.
The move would also put Mr. Pompeo, who has been immersed in the details of Pyongyang’s nuclear program, in a central role in running the negotiations with Kim Jong-un, the North Korean dictator whom Mr. Trump has said he will meet by May.
For all the criticisms of Mr. Tillerson — and there were many, particularly in the State Department as he moved to slash its size — he was considered a restraining influence on Mr. Trump. Mr. Pompeo, in contrast, has been an enthusiastic defender of the president’s policies, to the point that many senior current and former C.I.A. officials worried that he was far too political for the job.
In his public comments — including his dubious contention on Sunday that Mr. Trump has done more to constrain North Korea than any other president — Mr. Pompeo seemed to know that he would likely soon switch from giving the president his daily intelligence brief to carrying out Mr. Trump’s blunt “America First” vision worldwide.
“We’ve had a very good chemistry right from the beginning,” Mr. Trump told reporters at the White House on Tuesday morning as he described his relationship with Mr. Pompeo.
Chemistry is vital between any president and his chief global emissary. But the shift disrupts the delicate balance of power in the administration’s national security team.
Mr. Tillerson and Jim Mattis, the defense secretary, had run something of a tag team to keep the president in check, finding common ground on policies from the Middle East to East Asia before stepping into the Situation Room. For the better part of a year, that put Mr. Trump in the position of having to overcome their unified advice, which also was sometimes aligned with the White House national security adviser, H.R. McMaster.
One senior administration official who often sat in the backbenches of those meetings last week described Mr. Trump’s growing frustration at being hemmed in by his two principal national security cabinet members.
That seems particularly true on Iran, and Mr. Trump singled that issue on Tuesday as he was preparing to leave for California. He said he and Mr. Tillerson “disagree on things.”
“When you look at the Iran deal — I think it’s terrible. I guess he thought it was O.K.,” the president said, referring to Mr. Tillerson. “I wanted to either break it or do something. And he felt a little bit differently.”
His comments are certain to alarm European allies who have spent the last few days negotiating with Mr. Tillerson’s closest aide, Brian Hook, on a way to add to the agreement that limited Iran’s nuclear program, rather than reopen or scrap the deal. Those moves were intended to keep Mr. Trump from ditching the agreement in mid-May, when he faces a deadline over continued suspension of American nuclear-related sanctions on Iran.
The first Mr. Hook heard of Mr. Tillerson’s ouster was when a reporter for The New York Times called him for comment on Tuesday morning, shortly after the secretary’s 405-day tenure was ended by presidential tweet.
Mr. Tillerson’s denouement seemed rife with the symbolism of the change to come. After Mr. Trump was revealed to have referred to several African nations as “shithole” countries, he dispatched Mr. Tillerson on a lengthy trip to the continent last week to make it up to them.
But while the secretary was away, Mr. Trump agreed to the meeting with Mr. Kim, catching Mr. Tillerson by surprise — even though he was the one who had long been arguing for opening up a diplomatic channel to North Korea. While in Africa, Mr. Tillerson took a day off to recover from what the State Department said was exhaustion from long nights catching up by phone with Washington.
Then he got food poisoning, cut his travels short, and was fired upon landing in the United States.
It was clear in recent months that Mr. Tillerson and Mr. Trump were barely talking. The frequent dinners the chief diplomat shared with the president last spring, when the two men were forming their views of how to approach the world, had ended.
Mr. Trump had hired Mr. Tillerson because he liked his record of profits and expansion at Exxon, and thought his mane of white hair gave him the look of a secretary of state. But more recently, the president told aides he thought Mr. Tillerson was “weak” — the ultimate insult in Mr. Trump’s world. His affinity for Mr. Pompeo grew as the men bonded over intelligence warnings and authorizations for covert actions.
Mr. Pompeo’s rise will solve one central problem in American diplomacy over the past year: When Mr. Tillerson spoke, few thought he was speaking on behalf of the president.
“It creates the possibility that someone who is up to speed with the issues, and has a comfortable working relationship with the president, is now in the chair,” said Richard Haass, who served several Republicans and Democrats in senior state department and National Security Council positions.
America’s interlocutors, Mr. Haass added, will now believe the secretary of state “is speaking with the power and backing of the president.
“The question is whether, when President Trump speaks, it sounds like he has consulted his secretary of state,” Mr. Haass, now the president of the Council on Foreign Relations, said in a call from India.
The one arena where Mr. Pompeo’s views are still a mystery is Russia. While serving in Congress, he was a critic of President Vladimir V. Putin. As C.I.A. director, Mr. Pompeo said he believed intelligence assessments that Mr. Putin was behind the effort to influence the 2016 election — even though Mr. Trump has famously dismissed those reports for fear it would undercut the legitimacy of his election.
Mr. Pompeo has not, however, gone the next step to describe what he thought the United States should do to counter Russia’s actions.
In contrast, Mr. Tillerson had let known his increasing concern about Russia’s activities, and even about Mr. Putin, who famously presented him with an award for his deals with Russia while at Exxon. On Monday, his last day as secretary of state, he agreed with the British government that Russia was likely behind the nerve gas attack on a Russian living in England — while the White House has hedged about Russia’s responsibilities. Mr. Pompeo’s views are not known.
But perhaps the biggest unknown in the ascension of Mr. Pompeo is how it will affect any negotiations with North Korea.
He has warned many times, since last summer, that Mr. Kim is “a few months” away from acquiring the ability to strike the United States with a nuclear weapon. That is based on a calculation of how long it will take the North to solve the final problems of designing a warhead that can survive re-entry into the atmosphere atop an intercontinental missile.
But Mr. Pompeo also has been in charge of an active covert campaign against the North, which he has alluded to elliptically on several occasions. The question now is whether that covert effort — believed to include sabotage of North Korea’s supply chain and renewed cyber attacks on its missile and nuclear programs — will buy Mr. Trump enough time, and leverage, to make a negotiation work.
No agency has been more skeptical about the chances of Mr. Kim giving up his arsenal than the C.I.A. itself, under Mr. Pompeo.
In a presentation last fall at George Washington University, one of the agency’s top Korea analysts said that in the C.I.A.’s view, no amount of sanctions pressure would persuade Mr. Kim that it was worth giving up the weapons that he believes are his only defense from having his country overrun by the United States and its allies.
Associates of Mr. Pompeo says he shares that view — which would suggest that while he may soon be running the North Korea negotiations, his expectations of success are limited.
In retrospect, Tuesday’s shift could explain some comments Mr. Pompeo made over the weekend. In interviews on Fox and CBS, he said he had spent part of the weekend reviewing the C.I.A.’s internal history of American negotiations with North Korea for the past quarter-century. That would have been an odd way for a C.I.A. director to spend his reading time; it makes a lot of sense for a future secretary of state.