Boris Johnson, in an attempt to bring harmony to the top of Nato, will remind allies that it is “one for all, and all for one” in the quest to keep their people safe.

The Prime Minister’s words – echoing the famous phrase of The Three Musketeers, a novel written by renowned French author Alexandre Dumas – will have pointed resonance for French President Emmanuel Macron, who has played the role of agitator-in-chief in the run-up to Nato’s 70th anniversary preparations in London on Wednesday.

US President Donald Trump branded Mr Macron’s comments – saying that Nato was “brain dead” – as “very nasty” before the pair met on Tuesday at the US ambassador’s residence in London.

Mr Macron’s original comments were prompted by the Turkish offensive against the Kurds in northern Syria – regarded by most Nato members as key allies in the fight against so-called Islamic State (IS) – following the US decision to withdraw troops from the region.

Mr Macron later acknowledged in a tweet that his statements had “triggered some reactions” but said he stood by his remarks.

Leaders from the 29 Nato member states will start talks on Wednesday at The Grove, a country house hotel near Watford, having already attended a reception at Buckingham Palace, hosted by the Queen, and visited Downing Street on Tuesday evening.

The meeting in Hertfordshire is expected to consider new threats, including in the areas of cyber and space, after the alliance last month declared space one of its operational domains alongside air, land, sea and cyber.

In a rallying call to begin the discussions, Mr Johnson, whose predecessor Theresa May volunteered the UK to host the meeting, will remind the allies that their commitment to Nato has helped keep people across the globe safe since its inception in 1949.

Nato Leaders Meeting
French President Emmanuel Macron has issued a terse assessment of Nato in recent days (Daniel Leal-Olivas/PA)

“Seventy years on, we are rock solid in our commitment to Nato and to the giant shield of solidarity that now protects 29 countries and nearly a billion people,” Mr Johnson is expected to say.

“The fact that we live in peace today demonstrates the power of the simple proposition at the heart of this alliance: that for as long as we stand together, no-one could hope to defeat us – and therefore no-one will start a war.

“This essential principle is enshrined in Article 5 of the North Atlantic Treaty – that if any one of us is attacked, all of us will go to their defence. If Nato has a motto, it is, ‘one for all, and all for one’.”

Mr Johnson said the “doctrine of coming to one another’s aid” was the “single most important explanation” for why the British people and hundreds of millions of others lived in peace and freedom.

“Everything our peoples hold dear – from liberty and democracy to their jobs, homes, schools and hospitals – would not be secure and could not flourish without the peace that Nato is designed to guarantee,” the Conservative Party leader added.

Nato Trump
US President Donald Trump has been a vocal critic of Nato since being elected (Jonathan Brady/PA)

But the PM warned that peace “cannot be taken for granted” and said Nato members must “ensure our deeds match our words”.

He is set to lay out the UK’s own contribution to Nato’s defence ranks and highlight the “emerging threats” faced by the alliance, such as cyber warfare.

Mr Johnson is preparing to say: “For the UK’s part, we spend over 2% of GDP on defence.

“We are making the biggest contribution of any European ally to Nato’s readiness initiative by offering an armoured brigade, two fighter squadrons and six warships, including the Royal Navy’s new aircraft carriers.

“As allies and friends, we must never shy away from discussing new realities, particularly Nato’s response to emerging threats like hybrid warfare and disruptive technologies including space and cyber.”