Bolton grew up in a working-class family in Baltimore. He attended Yale College and Yale Law School on a scholarship, graduating with a law degree in 1974. At Yale, he befriended future Supreme Court Justice and fellow conservative Clarence Thomas.
In the early 70s, Bolton avoided being drafted into the Vietnam War by joining the Maryland National Guard. He later wrote that he "didn't want to waste time on a futile struggle."
Bolton's career in foreign policy began in the Reagan administration when he served in a variety of different positions in the DOJ and State Department.
Throughout his career, Bolton has been involved in some of the most controversial incidents in US foreign policy history, including the Iran-Contra affair. Bolton was assistant attorney general at that time.
next slide will load in 15 secondsSkip AdSkip AdWhile Bolton has worked in the federal government for the majority of his professional career, he's frequently been a critic of government bureaucracy and so-called "careerists," taking a more aggressive approach to policy in his own career.
Bolton's reputation as a maverick from his days at Yale carried over into his professional career, as he pushed unorthodox and hardline views on foreign policy and ruffled some feathers in the process.
Bolton under George W. Bush's administration was the Undersecretary for Arms Control, selected for the position by former Vice President Dick Cheney, a fellow defense hawk. One of Bolton's former aides described him as "Cheney's spy" to the New Yorker.
In that role, Bolton struck a deal to prevent the International Court Criminal — a frequent target of Bolton's criticism — from prosecuting Americans under international law.
Around that time, Bolton began publicly claiming that Cuba was developing nuclear weapons in coordination with Libya and Iran, despite pushback from the State Department, who said there was no evidence to support those claims.
next slide will load in 15 secondsSkip AdSkip AdThe New Yorker reported that Bolton forcefully retaliated against a fellow State Department official who questioned Bolton's claims, attempting to fire him and shutting out his boss.
From his position, Bolton played a major role in justifying the US invasion of Iraq by advancing the now-discredited position that Saddam Hussein was developing chemical weapons.
In one dramatic incident, Bolton flew to Europe to personally confront a Brazilian diplomat, Jose Bustani, who was advocating for Iraq to join the Chemical Weapons Treaty.
Iraq joining the treaty would have involved outside inspections to ensure the country wasn't developing chemical weapons, precluding the need for a foreign power to invade Iraq and oust Hussein.
Bolton reportedly demanded that Bustani resign and threatened him by saying “we know you have two sons in New York. We know your daughter is in London. We know where your wife is," which Bolton denies. Bolton then led an effort to oust Bustani from his position.
next slide will load in 15 secondsSkip AdSkip AdDespite the fact that no chemical or other weapons of mass destruction were found in Iraq, Bolton still stood by the US' invasion of Iraq and the subsequent years of war as recently as 2015.
In 2005, Bush nominated Bolton as the US' ambassador to the UN — an institution Bolton has regularly decried as useless and ineffectual.
The New Yorker described Bolton's reputation during his brief tenure at the UN as "abrasive but knowledgeable," often bristling with fellow diplomats. He did achieve, however, his goal of levying multilateral sanctions on North Korea.
After Bolton left the Bush administration in 2006, he harshly criticized it for dialing back sanctions on North Korea, describing the administration as mired in "ineffable sadness" and "intellectual collapse." Bush responded by saying he believed Bolton was "not credible."
In the next decade, Bolton worked as a Fox News contributor and earned money giving paid speeches. He also chaired the controversial Gatestone Institute, which has been criticized for peddling Islamophobia and misinformation about Islam.
next slide will load in 15 secondsSkip AdSkip AdBolton was initially passed over for secretary of state when Trump took office, but he joined the administration in March 2018 as national security advisor, replacing Gen. H.R. McMaster — who had taken a more restrained and measured approach to US policy before he left the administration.
Like Trump, Bolton is skeptical of international and multilateral institutions like the United Nations and the World Trade Organization, and prefers the US to take a unilateral approach to world issues.
Current and former national security officials told the New Yorker that Bolton is taking a more unilateral approach to policy within the US government itself, forgoing previously regular meetings with the Joint Chiefs of Staff and intelligence officials.
Bolton has long argued for the US to preemptively strike Iran and for the US to engage in regime change efforts, with one former official telling the New Yorker he's had an "anal focus" on the country for decades.
Bolton is now using his position to push the US towards a conflict with Iran. On May 5, he announced the US would be sending aircraft carriers and B-52 bomber planes to the Persian Gulf to counter any Iranian aggression.
next slide will load in 15 secondsSkip AdSkip AdSome Democratic members of Congress say Bolton and his allies are drastically overplaying Iran's threat to the US. Bolton has said the US is "not seeking war with the Iranian regime, but we are fully prepared to respond to any attack."
The Trump administration has also reportedly discussed a plan to deploy 120,000 US troops to the Middle East. While Trump has said he wants to avoid a conflict, he's threatened the US could cause "the official end of Iran" in a conflict.