Donald Trump recently proposed a bold idea, suggesting that the United States should have challenged NATO by invoking Article 5 to address the issue of illegal immigration at its southern border.

His proposition came shortly after he criticized the role of UK and NATO forces in Afghanistan during a Fox News interview, expressing doubts about the alliance’s reliability in supporting the US in times of need.

In a post on Truth Social Thursday evening, Trump suggested, “Perhaps we should have tested NATO’s resolve: by invoking Article 5, compelling NATO to assist in securing our Southern Border against illegal immigrant invasions, thereby allowing Border Patrol Agents to focus on other responsibilities.”

This statement aligns with Trump’s ongoing stringent immigration policies, as his administration has allocated a substantial $85 billion to the Immigration and Customs Enforcement (ICE), marking it as the most well-funded law enforcement agency in the US.

Article 5 is a crucial element of NATO’s foundation, declaring that an ‘armed attack’ against one ally is considered an attack against all 32 member nations.

NATO says it assesses on a case-by-case basis what triggers Article 5 – such as the ‘invasion by one state of the territory of another state’ – but clarifies that ‘events that lack an international element, such as purely domestic acts of terrorism, do not trigger’ the mutual defense clause, even though member states may choose to assist.

In the military alliance’s almost-80-year history, the mutual defence clause has only been invoked once – on the day following the September 11, 2001, terror attacks on the World Trade Centre in New York, which led to a US-led invasion of Afghanistan.

The US’s NATO allies at the time backed the American response in Afghanistan, where more than 1,000 non-American NATO soldiers were killed.

Donald Trump has suggested putting the world’s strongest military alliance ‘to the test’ in a controversial Truth Social post

In an interview with Fox News on Thursday, Donald Trump launched another onslaught of insults against Nato troops, claiming European personnel stayed ‘off the front lines’ in Afghanistan

Nato secretary general Mark Rutte delivered a reality check to Donald Trump, telling him that one Nato soldier died for every two Americans in Afghanistan after the US President doubted the Western alliance

ICE and other federal officers detain a person during protests as ICE operates in a residential neighborhood in Minneapolis, Minnesota, on January 13, 2026 

Trump’s latest Truth Social post comes just a day after he said of NATO: ‘We’ve never needed them – we have never really asked anything of them.’ 

The US President made the comments to Fox Business on the sidelines of the World Economic Forum in Switzerland on Thursday. 

‘You know, they’ll say they sent some troops to Afghanistan or this or that, and they did: they stayed a little back, little off the front lines,’ he added, in a remark which sparked fury in the UK.

The UK suffered the second-highest number of military deaths in the Afghanistan conflict at 457. The US saw 2,461 deaths. America’s allies suffered 1,160 deaths during the conflict – around a third of the total coalition deaths. 

Following Trump’s remarks, Labour MP Emily Thornberry, the chair of the foreign affairs committee, called it an ‘absolute insult’ to the 457 British service personnel killed in the conflict.

Speaking on the BBC’s Question Time, Dame Emily said: ‘How dare he say we weren’t on the frontline, how dare he. We have always been there whenever the Americans have wanted us, we have always been there.’

Liberal Democrat leader Sir Ed Davey said: ‘How dare he question their sacrifice?’ 

Conservative MP Ben Obese-Jecty, who served in Afghanistan, said it was ‘sad to see our nation’s sacrifice, and that of our Nato partners, held so cheaply’. 

Tory MP Ben Obese-Jecty, who served in Afghanistan as a captain in the Royal Yorkshire Regiment, said it was ‘sad to see our nation’s sacrifice, and that of our NATO partners, held so cheaply by the president of the United States’.

He said: ‘I saw firsthand the sacrifices made by British soldiers I served alongside in Sangin, where we suffered horrific casualties, as did the US Marines the following year.

‘I don’t believe US military personnel share the view of President Trump; his words do them a disservice as our closest military allies.’

Adding to the backlash, Calvin Bailey, a Labour MP and former RAF officer who served alongside US special operations units in Afghanistan, chimed in, saying Trump’s claim ‘bears no resemblance to the reality experienced by those of us who served there’. 

Tan Dhesi, chairman of the Commons Defence Committee, said the president’s comments were ‘appalling and an insult to our brave British servicemen and women, who risked life and limb to help our allies, with many making the ultimate sacrifice’. 

And Social Care Minister Stephen Kinnock said Trump’s claim was ‘deeply disappointing’.

British marines hold rifles during a patrol at the Bagram air base near Kabul 19 December 2001

US President Donald Trump delivers a speech during the Board of Peace session held as part of the 56th World Economic Forum (WEF) in Davos, Switzerland on January 22, 2026

The Department of Homeland Security has sent immigration agents to Maine as part of their latest crackdown on Somali migrants

‘There is no other way to say that, I don’t know really why he said them. I don’t think there’s any basis for him to make those comments,’ he told Sky News. 

‘We will always stand up for the values that we cherish: democracy, freedom, liberty to push back against dictators and anybody else that seeks to undermine our values and our way of life – and NATO is at the heart of that alliance.’ 

On Wednesday, Trump, in his meandering speech in Davos, hit out at NATO’s seeming unreliability: ‘I know them all very well. I’m not sure that they’d be there. I know we’d be there for them. I don’t know that they’d be there for us.’

But following the speech, NATO Secretary General Mark Rutte corrected the record to the US President, telling him: ‘There’s one thing I heard you say yesterday and today. 

‘You were not absolutely sure Europeans would come to the rescue of the US if you will be attacked. Let me tell you, they will, and they did in Afghanistan.’

Rutte’s rebuttal came after Trump called Denmark, which had the highest per capita death toll among coalition forces in Afghanistan, ‘ungrateful’ for US protection during the Second World War.

‘For every two Americans who paid the ultimate price, there was one soldier from another Nato country who did not come back to his family – from the Netherlands, from Denmark, and particularly from other countries,’ the NATO chief said.

‘So you can be assured, absolutely, if ever the United States were under attack, your allies will be with you. There is an absolute guarantee. I really want to tell you that because it pains me if you think it is not,’ Rutte added.

In an astonishing climbdown following his meeting with Rutte, the US President declared that the two had agreed ‘the framework of a future deal’ on Greenland as well as ‘the entire Arctic Region’.

It means Trump has now abandoned his plan to take over the semi-autonomous territory and dropped his threat to impose tariffs on the UK and seven other European nations for standing in his way.