Washington (CNN)For John Bolton, it was almost destined to end this way.The acrimonious departure of Donald Trump’s most recent national security adviser — his third in less than three years — was a predictable end to a relationship that was fraught from the start. For one thing, Bolton is a hawkish interventionist with a history of wanting to project American military might, while Trump has at least so far proven to have the instincts of an isolationist.On a personal level, Bolton has none of the rapport with Trump that other, more trusted advisers have cultivated. There’s no chance, for example, of Bolton hitting the golf course or sharing a bawdy joke with the President.Perhaps most importantly, Bolton’s ability to influence the President may have peaked on April 9, 2018 — the day he began his job at the White House. Over the previous several months, as Trump grew frustrated with his then-national security adviser, H.R. McMaster, he was receiving a steady barrage of advice from Bolton via Fox News. Bolton arguably had more direct influence over Trump as a talking head on his favorite cable news network than he did as a White House official down the hall from the Oval Office.Couldn’t agree to disagreeA Republican fixture for decades in Washington, Bolton’s reputation is as someone who prefers to speak his mind, not get in line. That certainly held true during his time in the Trump administration.After months of tension, the last straw for Bolton appears to be a dispute over Afghanistan on the eve of the anniversary of 9/11. A notable War on Terror hawk, Bolton opposed Trump’s idea to meet with Taliban officials this week at the Camp David presidential retreat in Maryland. That prompted a heated argument between Bolton and the President Monday night, as CNN reported. Bolton claims he offered to resign, while Trump says he fired Bolton because they “strongly disagreed” on policy. That’s true, though their disagreement went well beyond Afghanistan. In January of this year, as political unrest rocked Venezuela, Washington reeled after a photograph of Bolton revealed he had written “5000 troops to Colombia” on the top of a notepad. Whether it was a real proposal or a provocation on Bolton’s part, the administration never embraced any sort of military option in South America.Bolton long advocated tough talk toward the North Korean regime. He wrote in an op-ed for the London Telegraph in June 2017 that the Trump administration should not directly engage with Kim Jong-un and negatively characterized such plans as a “continuation of Obama policies.”A year later, now as the President’s national security adviser, Bolton took a back seat to Secretary of State Mike Pompeo as Trump met with Kim in their first one-on-one summit, in Singapore. After North Korea launched missile tests in May of this year, Bolton told reporters there was “no doubt” the actions violated United Nations resolutions. But Trump quickly took to Twitter to contradict Bolton and downplay his concerns, while expressing his “confidence” in Kim.”North Korea fired off some small weapons, which disturbed some of my people, and others, but not me,” Trump tweeted. “I have confidence that Chairman Kim will keep his promise to me…”Bolton was at odds with Trump in other areas, including Syria, the Iraq war and Vladimir Putin. In the same Telegraph op-ed in 2017, Bolton warned Trump that the Russian leader would lie to the President about everything from election interference to the Middle East. “Negotiate with today’s Russia at your peril.”Thirteen months later, Trump met with Putin in Helsinki and during a joint press conference appeared to side with Putin, whose denial that Russia had interfered in the 2016 presidential election contradicted the conclusions of Trump’s own intelligence agencies. Bolton, a member of the US delegation, was sitting feet away in the front row.No rapport with TrumpBolton might have survived longer if the division with Trump was just over policy. But the career Republican bureaucrat had little in the way of a personal relationship with the President that could have bridged the gap.Unlike Pompeo or South Carolina senator Lindsey Graham, Bolton is not prone to backslapping or telling off-color jokes to establish rapport with Trump. Bolton does not golf, a favorite pastime of the President’s and where people like Kentucky senator Rand Paul — Bolton’s ideological foe — can get Trump’s ear.Perhaps most humiliatingly, Trump even occasionally referred to his national security adviser as “Mike Bolton.” By contrast, Pompeo is particularly friendly with Trump, which has given the Secretary of State the upper hand in power struggles on the national security team.After Bolton praised the Libya of model for denuclearization — whereby dictator Moammar Gadhafi abandoned his own nuclear program, only to have US-backed rebels depose and kill him a few years later — shortly before last year’s summit with North Korea’s Kim, Trump was angry his aide was suggesting Kim could be similarly deposed. Pompeo used the remark to successfully encourage Trump to exclude Bolton from a high-profile Oval Office meeting with North Korean diplomat Kim Yong Chol.On the inside looking outBolton undoubtedly arrived on Trump’s radar during his tenure as a Fox News contributor throughout the Barack Obama administration. He was a harsh critic of Obama’s foreign policy decisions, frequently blasting negotiations with Iran over its nuclear program in appearances on Fox and in op-eds. During a 2015 appearance at a Republican party summit in New Hampshire while he was considering a run for the White House, Bolton called the eventual nuclear deal, officially known as the Joint Comprehensive Plan of Action, the “greatest display of appeasement from a president in history.”After Trump’s election, Bolton shifted his commentary toward advice for the new president. He broke through most successfully over the issue of Iran, since he and Trump were both staunch opponents of the nuclear deal.Bolton’s ability to influence the President’s decision to break the agreement not only illustrates Bolton’s masterful maneuvering from outside the White House, but also Trump’s penchant for being skeptical of those around him. In 2017, as Trump faced a periodic decision about whether to recertify Iran’s compliance with the deal, his national security team worked to encourage the President to do so, at least until the administration could finalize its Iran policy. According to a law passed by Congress, the President was required to certify Iran’s compliance every 90 days. But Trump was reluctant to even give this perfunctory approval to a deal that he had consistently opposed as a candidate.According to reporting in the Weekly Standard, days before the July 17, 2017, deadline, the White House had begun preparing to recertify, despite Trump’s frustration that he was not provided by his team with options to back out of the deal or decertify Iran’s compliance. The morning of July 17, according to sources familiar with what took place, White House strategist Steve Bannon gave Trump a printout of Bolton’s latest column for the Hill newspaper. The title was “Trump Must Withdraw from the Iran Nuclear Deal — Now.”Bolton’s op-ed attempted to take advantage of what one former senior White House official described as the President’s reliance on advice from “outside the room.” The future Trump administration official blasted “JCPOA supporters” within the administration who were insisting that “rejecting the deal would harm the United States.” Bolton called that “nonsense.” It was also what most of Trump’s national security team had been arguing in favor of.Trump abruptly decided to reverse his decision and instructed his administration to no longer recertify the deal. An hours-long scramble by his national security team eventually convinced Trump to reverse his reversal and proceed to recertify Iran’s compliance. But it would be the last time the President would do so before exiting the deal entirely.What Bolton provided in that particular moment was an option Trump had felt was withheld from him by the insiders in the Oval Office. But Bolton lost that advantage once he became one of those insiders. Combined with the rigidity of his own views and his lack of a personal relationship with Trump, accepting the job as national security adviser was Bolton’s undoing as a voice in Trump’s ear.