FILE - In this Dec. 13, 2018 file photo, national security adviser John Bolton unveils the Trump Administration's Africa Strategy at the Heritage Foundation in Washington. (AP Photo/Cliff Owen, File)

WASHINGTON (AP) — John Bolton was in Mongolia.

More than 1,200 miles away, President Donald Trump orchestrated an image for the world’s front pages by becoming the first U.S. president to set foot in North Korea, shaking hands with Kim Jong Un on the north side of the demilitarized zone.

The distance was telling.

Bolton, a longtime critic of diplomacy with North Korea, had scheduled his foray to Mongolia weeks before Trump’s impromptu invitation to meet Kim. But the national security adviser’s isolation at such a high-profile moment underscored the growing disconnect between the two men.

Their repeated clashes on policy and style reached an exclamation point Tuesday when Trump ousted Bolton with a tweet.

This account of how their relationship unraveled is based on interviews with current and former administration officials and Republicans close to the White House. They spoke on condition of anonymity to discuss private deliberations.

It was a marriage that was never going to last: Trump and Bolton rarely saw eye to eye on global hotspots. The national security adviser held far more hawkish views than the “America first” president on matters like Iran, North Korea and Afghanistan.

“John Bolton is absolutely a hawk,” Trump told NBC in June. “If it was up to him, he’d take on the whole world at one time, OK? But that doesn’t matter because I want both sides.”

Trump does value disagreement and jockeying among his staff. But he came to believe that Bolton’s presence spooked foreign leaders. And he eventually grew weary of the national security adviser’s bureaucratic knife-fighting.

By the spring, Bolton found himself cut out of important White House meetings and the president’s perceived diplomatic triumphs, including the historic visit to North Korea.

As Trump met with Kim, Bolton was photographed shaking hands with Mongolia’s secretary of state — an image that decidedly did not lead cable news.

While Trump’s visit to Kim was a spectacle largely of his own making, Bolton’s more modest outreach to Mongolia was similarly his own grand design, meant to check Russian and Chinese influence in central Asia.

The two trips encapsulated their opposing world views.

In the hours before Bolton left Trump in Seoul to head for Ulaanbaatar, Bolton was in a meeting with the president in which Trump paid tribute to the officials with him — or at least tried to.

“And Secretary of State Pompeo is here,” Trump said. “Mike Bolton — John Bolton — is here.”

Reporters spotted Bolton glowering at the slight. It would not be the last.

The president has spent a career fixed on image, prizing striking looks and frequently boasting about family members and Cabinet officials who look like they “stepped out of central casting.”

Bolton’s bushy mustache simply didn’t fit the part.

Bolton, a former ambassador to the United Nations and then a fixture on Fox News as a national security commentator, nearly entered the 2016 presidential campaign himself to push his hard-nosed foreign policy.

His neoconservative credentials never meshed with the isolationist vibe of Trump’s campaign but, during the presidential transition, there was Bolton striding through the gilded lobby of Trump Tower to meet with the president-elect.

Bolton didn’t get a job just then.

Trump later told confidants that the hawk’s trademark mustache would never be a fit in his administration. But Trump kept an admiring eye on Bolton’s frequent cable TV appearances, during which he often defended the policies of the president even when they ran counter to what he had preached for decades.

Trump’s first national security adviser, Michael Flynn, resigned barely a month into the job and was soon charged with lying to the FBI. His second, H.R. McMaster, grated on Trump’s nerves with his long-winded, detail-oriented presentations.

Bolton became the unlikely choice to be Trump’s third, thanks largely to the strength of his television appearances.

But while TV helped Bolton get the job, it also helped him lose it.

As pressure mounted on the White House this summer amid signs of an economic slowdown and growing global discord, Trump has increasingly prioritized aides who are willing to defend him on television.

Bolton was tentatively booked to appear on a pair of Sunday talk shows in late August but backed out, saying he was not comfortable defending some of the administration’s plans. That drew the president’s ire, according to a White House official who spoke on condition of anonymity because the aide wasn’t authorized to discuss private conversations.