Security hawk flies in with an untouchable ‘tache

A treasured memento from John Bolton’s years in the Reagan administration is the defused hand grenade he keeps in his office.

Some White House officials will see him as a live grenade with the pin pulled out when he works alongside them.

Bolton, 69, a veteran US government official and uncompromising hawk who believes in the use of American military might, was announced last week as Donald Trump’s third national security adviser in just 14 months.

His appointment comes amid unprecedented turbulence in American foreign policy. Trump has fired his secretary of state, Rex Tillerson, has stunned his advisers by agreeing to meet the North Korean dictator, Kim Jong-un, and is contemplating abandoning the Iran nuclear deal.

Bolton, who also opposes the Iran deal - he once likened Tehran getting a nuclear weapon to ‘‘Hitler marching into the Rhineland’’ - has spoken in favour of pre-emptive wars with Iran and North Korea.

Last month, in The Wall Street Journal, he argued the ‘‘legal case for striking North Korea first’’ to end the ‘‘imminent threat’’ from its nuclear programme.

Bolton is likely to be highly sceptical of the value of Trump meeting Kim.

A former US ambassador to the UN under President George W Bush, he has long railed against ‘‘the bureaucracy’’ in Washington, commenting that the US state department was ‘‘genetically wired to try to bring secretaries of state to their corporate view’’.

But Bolton is also a highly skilled official whose bureaucratic knife-fighting skills, intelligence and work ethic are praised even by his detractors.

Trump considered him when initially selecting his cabinet, but was said to be fixated on Bolton’s facial hair.

‘‘Bolton’s moustache is a problem,’’ the former Trump chief strategist, Steve Bannon, told the author Michael Wolff. ‘‘Trump doesn’t think he looks the part.’’

Bolton responded to reports of this by tweeting: ‘‘I appreciate the grooming advice from the totally unbiased mainstream media, but I will not be shaving my #mustache.’’

Instead, he won over Trump by combative appearances on Fox News and a series of discreet meetings in the White House in which he told the president that his foreign instincts were correct and he should stop being dissuaded by traditionalist advisers.

One source said Tillerson was sacked soon after Bolton returned from London to tell Trump that the foreign secretary, Boris Johnson, had said to him that Tillerson was admired in Europe for his "flexibility" over policy - a trait neither Bolton nor Trump appreciates.

Like his new boss, Bolton is forthright and unafraid to trade insults.

When Bolton referred to Kim Jong-il as a ‘‘tyrannical dictator’’, the father of the current leader in Pyongyang responded by calling him ‘‘human scum’’, which Bolton viewed as a badge of honour.