The strange political marriage between President Trump and his most recent national security adviser, John Bolton, has come to a sudden end. Like most troubled relationships, both sides claim to have taken the initiative in calling it quits. Trump announced on Twitter that he had "asked John for his resignation" the night before. Bolton later insisted that he had initiated the split first, and that Trump had replied, "Let's talk about it tomorrow."

More pressing for Republicans, however, is the growing disconnect between their party leader and most of the rest of the GOP on national security policy. Bolton's departure is the latest in a string of traditional-to-hawkish thinkers from Trump's inner circle, and it comes at critical junctures in hot spots around the world.

When Trump first took office, one of the more remarkable aspects of his early team was his reliance on generals in key national security positions. Former Gen. Michael Flynn was his first national security adviser. When he resigned under scandal, he was replaced by then-Gen. H.R. McMaster. Trump appointed then-Gen. John Kelly as secretary of homeland security, moving him over to White House chief of staff when Reince Priebus could not get the West Wing under control. Most prominently, James Mattis went directly from commandant of the Marine Corps to secretary of defense, an unusual step that prompted some concerns that the military might have too much influence over civilian command.

One by one, each of them has been pushed off the stage. This trend indicates a real conflict between the national security establishment in and out of the military and Trump's populist outlook — perhaps most so with Bolton's exit.

Bolton's appointment raised eyebrows from the start. Trump embraced the non-interventionist faction of the GOP from the moment he entered the race, attacking the mainstream of the Republican Party's foreign policy outlook. He famously tore into the Bushes for the war in Iraq during the 2016 presidential primaries and campaigned heavily on the promise to get the U.S. out of foreign entanglements, especially in Afghanistan. Trump insisted that he would do so by "winning" on the way out, but it was clear that Trump distrusted interventionists and detested the nation-building philosophy of neoconservatism.

Hiring Bolton to replace McMaster may have been intended to send a signal of continuity in March 2018, but if anything, Bolton exemplified everything that Trump ran against. Bolton has advocated muscular American interventionism in the Middle East and elsewhere as a means to advance our national security interests. He embraced George W. Bush's admonition to fight terrorists abroad rather than waiting to fight them at home, a major rationale for the continuing wars in Iraq and Afghanistan. Even more than most other Republicans, Bolton advocated for hard-line approaches to Iran and North Korea. Bolton's appointment made mainstream hawk Mike Pompeo, who had recently moved from CIA director to secretary of state, look somewhat dovish by comparison.

The most surprising aspect of Bolton's exit was that it didn't happen sooner. The catalyst for it appears to have been the aborted peace talks with the Taliban, which were proposed to be held at Camp David this week. But it might just as well have been Trump's insistence at going forward on a third summit with Kim Jong Un, or fourth summit if one counts the DMZ handshake. Bolton surely has been pushing back on Trump's suggestions to meet with Iran's Hassan Rouhani in a similar manner, especially with Bolton having explicitly advocated for a military response for years.

This appears similar to the conflict between Trump and Mattis at the end of last year. While Kelly was quietly moved out of the White House and McMaster was cashiered for murky reasons, Mattis made it publicly clear why he left the Pentagon: Trump wanted an immediate and complete withdrawal from Syria and declared that the U.S. had defeated ISIS to justify it. Mattis immediately objected and argued that a U.S. withdrawal would betray allies and lead to an ISIS resurgence. Mattis announced his retirement over the difference, but Trump ended up dismissing him — although he also scaled back the U.S. withdrawal from Syria and Iraq.

One could propose that Trump's reliance on the generals, as well as Bolton's hiring, was intended to build the oft-claimed "team of rivals" around a president, but that doesn't fit Trump's temperament or instincts. It looked more like an attempt to knit all Republican factions together in the same administration to show that they can co-exist within a broad coalition. Unfortunately, Bolton's exit — and that of other key national security team members — suggests the opposite is true.

This disconnect will force a day of reckoning on national security and foreign policy between Trump and GOP leadership, almost certainly sooner rather than later. Mattis has been circumspect about his relationship with Trump in public, but his new memoir on leadership and foreign policy stresses the values of teamwork and alliances, both of which Trump's instincts discount. Bolton will likely be more vocal and direct about his conflicts with Trump on policy, even without a memoir to sell.

The debate that arises will test Republicans' ability to overlook Trump's non-interventionist impulses at a time when Trump needs as much party loyalty as possible. As his re-election bid approaches, Trump might need to make more of an effort to find middle ground with his party's desire to project American power around the world, or risk losing too many allies at home to keep those peace efforts going.

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