The North Atlantic Treaty Organisation, formed as the Cold War got under way, is on Thursday marking its 70th anniversary. Russia, after an attempt at detente, is once again the adversary under Vladimir Putin, but the alliance is also facing sustained attacks from an unexpected quarter – the US president.

The commemoration of this birthday would, at other times, have been a lavish occasion. But it will be a subdued affair this year when Nato ministers meet in Donald Trump’s Washington with everyone fully aware that this American president regularly berates them while offering little criticism of Russia and none at all of Putin.

Western leaders have become used to the state of affairs.

At a Nato summit in Brussels last July, Trump hurled insults at member states and made false claims about personally forcing them to raise defence spending, before telling Theresa May on a visit to Britain to go for a hard Brexit – the European Union being another western body he dislikes.

Trump then went on to show an adulatory attitude to the Russian president at their summit in Helsinki, drawing widespread opprobrium.

Nato leaders gather for summit: in pictures Show all 10 1 /10 Nato leaders gather for summit: in pictures Nato leaders gather for summit: in pictures World leaders gather for Nato family photo Getty Images Nato leaders gather for summit: in pictures British Prime Minister Theresa May arrives EPA Nato leaders gather for summit: in pictures President Donald Trump talks to British Prime Minister Theresa May EPA Nato leaders gather for summit: in pictures U.S. President Donald Trump, left, talks to British Prime Minister Theresa May during a family photo at a summit of heads of state and government at NATO headquarters in Brussels Wednesday, July 11, 2018. NATO leaders gather in Brussels for a two-day summit to discuss Russia, Iraq and their mission in Afghanistan. (AP Photo/Markus Schreiber) Markus Schreiber AP Nato leaders gather for summit: in pictures US President Donald Trump and Nato Secretary General Jens Stoltenberg attend a bilateral breakfast ahead of the Nato Summit in Brussels Reuters Nato leaders gather for summit: in pictures President Donald Trump, right, gestures as he speaks to the media prior to his bilateral breakfast with Nato Secretary General Jens Stoltenberg, left AP Nato leaders gather for summit: in pictures President Donald Trump, US Secretary of Defence James Mattis and US Secretary of State Mike Pompeo at the bilateral breakfast with Nato Secretary General Jens Stoltenberg REUTERS Nato leaders gather for summit: in pictures President Donald Trump and Mike Pompeo, left, are reflected in a mirror as they attend at a breakfast meeting AFP/Getty Images Nato leaders gather for summit: in pictures President Donald Trump speaks during the bilateral breakfast EPA Nato leaders gather for summit: in pictures President Donald Trump gestures during the bilateral breakfast EPA

The extent of the fracture of relationship between the Trump administration and western allies was embarrassingly evident at the recent annual Munich security conference.

“To all of you, I bring greetings from a great champion of freedom and of strong national defence ... I bring greetings from the 45th president of the United States of America, president Donald Trump,” declared vice president Mike Pence as he waited for the applause, his head slightly bowed as if in homage to the leader. But instead of applause there was deafening silence.

After a painfully prolonged pause, the US vice president continued with his speech, at a gathering considered to be particularly important this year with the Middle East, Isis and terrorism, conventional and trade wars, cyberattacks and climate change all on the agenda.

We know the vice president was expecting evocation of Trump to be greeted with enthusiastic clapping – a copy of his prepared address provided by the White House marks the pause for “applause” after the opening lines.

Angela Merkel, in a combative response, warned of the dangers of American isolationism, staunchly defended multilateral institutions under threat from current US policy, and spoke up for the effort being made by Europe, as well as Russia and China, to save the Iran nuclear deal from attempts by Trump to destroy it.

The German chancellor spoke before 30 heads of government and 90 ministers. Her speech was greeted with a prolonged standing ovation in the packed auditorium.

Jens Stoltenberg, the Nato secretary general, has taken a markedly more emollient stance with Trump, not rising to the diatribes at the Nato meeting, overlooking the president’s more fanciful claims, and maintaining the US president has created a “new sense of urgency” among member states on military spending.

Stoltenberg, a former Norwegian prime minister who has just had his tenure at Nato extended, met with Trump at the White House on Tuesday.

The president tweeted: “Jens Stoltenberg, NATO Secretary General, just stated that because of me NATO has been able to raise far more money than ever before from its members after many years of decline. It’s called burden sharing. Also, more united. Dems & Fake News like to portray the opposite!”

Trump’s claim about his supposed personal achievement on Nato spending is untrue. But it does remain the case that successive American presidents have asked Nato countries to raise their defence budget to 2 per cent of GDP, with very limited success.

Germany, one of the wealthiest countries in the alliance, this month announced a goal to spend 1.5 per cent by 2024, only aiming an increase to 2 per cent following a subsequent lengthy period.

Britain is one of the few member states which claims to be have reached the 2 per cent benchmark, although there are accusations from some critics that this was achieved with a degree of creative accounting in Whitehall.

Nato’s 70th summit will take place in Britain in December. It is not often remembered that the idea of the alliance first came from this country, raised by Ernest Bevin, the foreign secretary in Clement Attlee’s Labour government in 1948, who then nurtured the vision to fruition through dialogue with European states and the US.

What we have is unprecedented, we are at the 70th anniversary but the first time where allies have doubted the commitment of the American president Doug Lute, US envoy to Nato under then president Barack Obama

The UK is, of course, scheduled to be out of the European Union by that time. Whatever happens on that score, however, would not affect Nato membership, although a post-Brexit government in London seeking a trade deal with the US may have to decide where it stands if the rift between Trump and European allies continues to grow.

Two former US ambassadors to Nato have described what they consider to be the real problem facing the alliance.

“What we have is unprecedented, we are at the 70th anniversary but the first time where allies have doubted the commitment of the American president,” held Doug Lute, who was one of the envoys under Barack Obama.