Washington — Rex Tillerson is off to an agonizingly slow start as secretary of state. That matters, because if Tillerson doesn’t develop a stronger voice, control of foreign policy is likely to move increasingly toward Stephen Bannon, the insurgent populist who is chief White House strategist.

Tillerson’s State Department has been in idle gear these past two months. He doesn’t have a deputy or other top aides. His spokesman can’t give guidance on key issues, because decisions haven’t yet been made. Tillerson didn’t attend important meetings with foreign leaders.

As a former chief executive of Exxon Mobil, Tillerson is accustomed to a world where a visible display of power is unnecessary, corporate planning is meticulous, and office politics are suppressed. But this is Washington.

“I am an engineer by training. I seek to understand the facts,” Tillerson said at his confirmation hearing. That sounds reassuring, but it doesn’t fit the glitzy, backstabbing capital that spawned the television series “House of Cards.”

“He may pay some cost up front for not meeting Washington expectations,” notes Stephen Hadley, national security adviser for President George W. Bush and a Tillerson supporter. “The short-term buzz was that he’s out of the loop, but Tillerson is playing for the long game.”

Tillerson’s future impact at State depends on his relationship with President Trump, but so far, that has seemed lukewarm. Tillerson’s candidate for deputy, Elliott Abrams, was rebuffed — reportedly at Bannon’s urging — after Trump had seemed initially supportive. Strangely, the 64-year-old Tillerson’s best opportunity is his friendly relationship with Jared Kushner, Trump’s peripatetic 36-year-old son-in-law and adviser.

An example of the role Tillerson could play is an exchange in February about the Foreign Corrupt Practices Act. During a White House meeting, Trump complained that the anti-bribery statute cost America billions of dollars in lost sales overseas and millions of jobs. According to one insider, Tillerson dissented and described how he had walked away from an oil deal in the Middle East after a leader there demanded a payoff — but later was invited back.

“You’re Exxon!” Trump countered, but the former CEO dissented again. “No, people want to do business with America.” This pushback from an experienced person is what Trump needs — as in Defense Secretary James Mattis’ rebuff on the efficacy of torture.

Tillerson’s first big setback was his failed advocacy of Abrams, an experienced former State Department official. From the beginning, Bannon was a problem. Back in December, a prominent Republican personally recommended Abrams to Bannon, but Bannon said the administration didn’t need someone who was outspoken as “a globalist, an interventionist, a neoconservative.” Tillerson persisted and offered Abrams the job in early January.

Trump seemed enthusiastic at an Oval Office meeting on Feb. 7 that included Tillerson, Kushner and Abrams, and as they were leaving the Oval Office, Bannon, in a true “House of Cards” moment, said to Abrams: “Huge fan.”

Several hours later, reportedly after Bannon showed Trump some critical comments Abrams had made about him during the campaign, Tillerson was informed that the nomination had been nixed. Tillerson tried to reverse the decision but failed. He’s still looking for a deputy.

The dilemma for Tillerson, the methodical engineer, is how to connect with the mercurial tweeter-in-chief. A fascinating example was Tillerson’s conversation with the president just before Trump placed a telephone call to Turkish President Recep Tayyip Erdogan. Tillerson tried to explain the tricky Kurdish problem in detail, but that wasn’t what engaged Trump, according to one well-informed source.

The president interjected with an explanation of why Erdogan had survived an attempted military coup last summer: “You know what saved him? Facebook and social media.” It was a revealing, and probably accurate, presidential insight.

Trump’s business pragmatism may be the best hope for a coherent foreign policy that avoids Bannon’s self-proclaimed goal of “deconstruction” of the established order. A telling example was when Tillerson and Kushner advised him last month that Chinese President Xi Jinping wouldn’t talk on the phone until Trump clarified that he supported the longstanding “one China” policy. Trump is said to have responded: “So clarify.”

Tillerson and Mattis can be the nexus for sound international strategy, working with Lt. Gen. H.R. McMaster, the new national security adviser. As was said of Hillary Clinton and Bob Gates when they were secretaries of state and defense, respectively, this would be the “Adult Swim” group, checking a noisy, chaotic, ideological White House.

But first Tillerson must get in the pool and start making some waves.

— David Ignatius is a columnist for Washington Post Writers Group.