"If you want peace, prepare for war" – those are the words quoted by Donald Trump's next national security adviser.
John Bolton was quoting the Roman dictum as he was interviewed by Sky News following the announcement that he is to replace HR McMaster.
He said: "The US and the west face a lot of threats.
"I think we've seen proliferation, terrorism, strategic threats. So despite the view of many people at the end of the Cold War that we'd come to the end of history, unfortunately we haven't.
"It's important for the US to protect its civilian population, protect its alliances, protect its economy, so there will be a lot of work to do."
When asked about the potential for more conflict, he replied: "I think that's something we want to avoid and I think the way the President has approached this along the line of Ronald Reagan of peace through strength is important.
"And I think the surest way to avoid conflict is to have a strong military capability.
"As the ancient Romans used to say: Si vis pacem, para bellum – if you want peace, prepare for war."
Mr Bolton, a hawk who has advocated military force against Iran and North Korea, will become the third person to hold to national security adviser position in 14 months.
He served as the US ambassador to the UN from 2005-2006 and as Under Secretary of State for Arms Control and International Security from 2001-2005.
In a statement, the White House described him as "one of the strongest voices and experts on the full range of national security issues and challenges facing the country".
President Trump announced the move on Twitter, saying: "I am very thankful for the service of General HR McMaster who has done an outstanding job and will always remain my friend."
Mr Bolton, 69, will take over officially on 9 April.
With Secretary of State Rex Tillerson being replaced by CIA boss Mike Pompeo, the national security team is increasingly staffed by those sharing the President's preference for exercising US power unilaterally.
Under president George W Bush, Mr Bolton pushed the invasion of Iraq, which was later found to have been based on exaggerated intelligence.
More recently, Mr Bolton has been a media commentator – including on Sky News – and has pushed tough positions on North Korea and the 2015 Iran nuclear deal, which Mr Trump has criticised.
Speaking to Sky News after his position was confirmed, Mr Bolton said among the issues he will focus on will be the dangers posed by nuclear proliferation and terrorism.
But he was tight-lipped on what he had discussed with the President on these subjects, saying: "I don't talk about my conversations with the President.
"I think that's important for an adviser…you can't have a full and frank discussion if the advice is public."
There had been growing speculation that General McMaster would soon be ousted, having clashed regularly with President Trump.
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The three-star general was brought in to replace the disgraced Michael Flynn.
His departure is the latest in a long line that started with Mr Flynn but has also included chief of staff Reince Priebus, chief strategist Steve Bannon, economic adviser Gary Cohn and Anthony Scaramucci, who lasted just days as White House communications manager.