WASHINGTON (AP) -- John Bolton, President Donald Trump's incoming national security adviser -- and his third to date -- is a divisive foreign policy figure who was an unabashed supporter of the Iraq war and advocates regime change in Iran.
The rise of the mustached Bolton, a former U.N. ambassador under President George W. Bush who served in three federal agencies under Presidents Ronald Reagan and George H.W. Bush, is likely to herald a rightward shift in Trump's foreign policy and an embrace of more hard-line policies.
Bolton, 69, has been an especially outspoken critic of the Iran nuclear agreement. Trump had campaigned against the deal and vowed to end it, but instead heeded the advice of two outgoing aides, national security adviser H.R. McMaster and Secretary of State Rex Tillerson, to delay the move.
Since firing Tillerson and announcing his intent to replace him with CIA Director Mike Pompeo, Trump has signaled he is eager to make good on his promise on Iran. On Tuesday he coyly said, "You're gonna see what I do."
Trump had originally considered choosing Bolton, a Fox News contributor, as his secretary of state. But Bolton's background complicated his chances for Senate confirmation.
When George W. Bush became president, Bolton served as the State Department's point-man on arms control, where he battled other governments over nuclear weapons tests, land mines, biological weapons, ballistic missile limits and the International Criminal Court.
An unabashed proponent of American power and a strong supporter of the Iraq war, Bolton was unable to win Senate confirmation after his nomination to the U.N. post turned off many Democrats and even some Republicans. He resigned after serving 17 months as a Bush "recess appointment," which allowed him to hold the job on a temporary basis without Senate confirmation.
In recent years, Trump has denounced the U.S. invasion of Iraq, describing it as a waste of lives and money -- though his contemporaneous views were less clear. He has also been critical of Bush and Republicans for their support of the nearly nine-year conflict, which saw more than 4,400 American service-members killed and more than 31,000 wounded.
Bolton has maintained a pair of political committees, which he has used to funnel political support to hawkish candidates. The top donor to the groups was Robert Mercer, who has given $5 million to Bolton's super PAC in recent years.
Mercer was also a top supporter of Trump's campaign.
Bolton, who was born in Baltimore and graduated summa cum laude from Yale, briefly flirted with running for president in 2015, making campaign trips to early states and candidate cattle-calls. He and Trump have met regularly since Trump took office.
Bolton is Trump's third national security adviser. He brought in McMaster to replace Michael Flynn, who, along with Trump's deputy campaign chairman Rick Gates and campaign aide George Papadopoulos, has pleaded guilty to lying to the FBI. Flynn is now cooperating with investigators looking into potential collusion between Russia and Trump's campaign and other potential misdeeds by Trump and those in the president's orbit.