5 facts about John Bolton, Trump's new national security adviser

National Security Adviser H.R. McMaster was added to the growing list of former White House officials Thursday when President Trump announced he was replacing McMaster with former ambassador to the United Nations John Bolton.

Bolton is a hawk's hawk who has repeatedly said he believes the United States has the right to take the first shot to handle potential threats.
Several commentators have expressed concern that Bolton's bellicose approach will only encourage Trump's more aggressive foreign policy instincts and could help lead the United States into what might be otherwise avoidable military conflicts.
Here are some facts from Bolton's past that help show why his appointment has made some people nervous.

He thinks pre-emptive war with Iran and North Korea is the right call
In a February op-ed for The Wall Street Journal, Bolton made the "legal case for striking North Korea first" to stop what he deems an "imminent threat" from the nation's nuclear program.
Bolton is strongly opposed to the Iran nuclear deal and said on Fox News that the United States "has no other option" than to bomb the country. According to The American Conservative, "he has been obsessed for many years with going to war against the Islamic Republic."

He still thinks invading Iraq was the right call
In the run-up to the U.S. invasion of Iraq, Bolton joined other administration officials in expressing confidence that Saddam Hussein had weapons of mass destruction and that Iraqis would welcome the U.S. overthrow of the regime.
Both those predictions turned out to be incorrect, but unlike his new boss, Bolton still believes the invasion was the right decision.
"I still think the decision to overthrow Saddam was correct," Bolton told the Washington Examiner in 2015. "I think decisions made after that decision were wrong, although I think the worst decision made after that was the 2011 decision to withdraw U.S. and coalition forces."

He resisted efforts to investigate the Iran-Contra scandal
Bolton was working as an assistant attorney general in the Reagan administration during the Iran-Contra affair. During that investigation, Bolton argued that the Ethics in Government Act establishing an independent counsel was unconstitutional.
According to The Nation, Bolton "tried to torpedo" then-senator John Kerry's investigation into alleged drug smuggling and gun running by Reagan-backed contra rebels in the civil war against Nicaragua's Sandinista government.

He is not a big United Nations fan
When former president George W. Bush appointed Bolton to be ambassador to the United Nations it was pointed out that his nominee was not a fan of the organization.
In particular, critics pointed to his 1994 statement that, "The Secretariat building in New York has 38 stories. If it lost ten stories, it wouldn’t make a bit of difference. The United Nations is one of the most inefficient inter-governmental organizations going."
Bolton also said, "The United States makes the UN work when it wants it to work, and that is exactly the way it should be, because the only question, the only question for the United States is what is in our national interest. And if you don’t like that, I’m sorry, but that is the fact."

He once joked that Obama is a Muslim
During his 2016 keynote address to the American Freedom Alliance, Bolton managed to imply former president Barack Obama was both a Muslim and a monarch.
Bolton spoke of King Abdullah of Jordan, who he joked "is not simply a Muslim king of a Muslim country, unlike our president.”