The UK just might be on the verge of a Brexit-style rethink of its Nato membership

The sovereignty argument that was used to some effect by the Brexiteers is equally, if not more, relevant to our allegiance to the treaty organisation

Boris Johnson and Donald Trump at the UN headquarters in New York (AFP/Getty)

Earlier this autumn, a former British minister offered this reassurance to an international audience in Latvia concerned about UK defence engagement after Brexit. The UK might be leaving the European Union, he said, but Britons had always had misgivings about EU membership. They had never had any such doubts about membership of the North Atlantic Treaty Organisation (Nato).

Which got me thinking. What if the spotlight were to fall on the UK’s Nato membership in the same way as it has fallen for so many years on our EU membership. What then?

In just less than a week, London – or rather a secluded hotel in Hertfordshire – will host a Nato summit. It will bring together the 29 members of the alliance, celebrate the organisation’s 70th anniversary and consider directions for the future. At almost any other time, such a gathering of international leaders would be flaunted as a feather in the UK’s diplomatic cap. That is not quite how it looks now.

The summit, on 3-4 December, comes barely a week before the general election, and Boris Johnson will need to play it carefully. What might have been an opportunity to strut his stuff as the confident leader of the host nation and the second-most powerful Nato member after the United States, becomes less straightforward in the context of an election. Where does statesmanship stop and electioneering begin? Any misstep risks intruding into the campaign.

An even greater risk comes in the shape of Donald Trump, who will be making his first trip to the UK since his controversial state visit last year. The US president has been a very public supporter of Johnson, offering both applause and “helpful” advice. Any more of this next week, however, could be seen by voters as unwarranted interference. Johnson’s electoral fortunes are unlikely to be enhanced if he looks as though he is in Trump’s pocket. But how to keep the Tweeter-in-chief quiet?

Then there is the US president’s stance on Nato itself. Before he was elected, Trump suggested that the alliance was “obsolete” and should rethink its purpose. He has since insisted that he is a big Nato supporter, but that the Europeans need to pay their way – a message, to be fair, that successive US defence secretaries, including under President Obama, have also conveyed over the years.

Doubts about Trump’s commitment to the alliance nonetheless remain. He is reported to have talked about withdrawing the US from Nato on several occasions since he was elected. And even as the alliance continues to expand into the western Balkans, east and central Europeans in particular worry that they may not be able to count on Nato protection as they had hoped.

One consequence is some discreet and not-so-discreet thinking about a time when Europe might have to rely more on itself for its defence.

President Emmanuel Macron has been at the forefront of those advocating an EU military and defence capability, even a European army – though many, including the UK, Germany and many of the east and central European countries that joined Nato after the collapse of the Soviet Union are opposed. They still hope that the Atlantic shield will retain its potency.

Which takes us back to the UK. Defence has not – so far – featured prominently in this election, even though there is a sharp difference between Johnson’s enthusiastic Atlanticism and Jeremy Corbyn’s lukewarm support for Nato and his history of opposition to the UK military interventions. Defence could though spring upon the scene if the Scottish National Party, which wants to scrap the Trident nuclear deterrent, were to become a player following the election of a hung parliament.

And in some ways, a national defence debate could be a logical extension of the Brexit argument, if and when the UK really does leave the EU. There have been impassioned disagreements about defence in the past. There were the CND marches of the 1950s; the 1964 general election was fought in part on the divisive issue of Britain’s nuclear deterrent, and there were vehement protests in the 1980s against US plans to station cruise missiles in Europe – a move that opponents feared would make the European cities targets in the event of a US-Soviet war.

The new circumstances in which the UK will find itself could well lead to some of the very same arguments employed by the Brexiteers being applied to defence – and specifically to the UK’s membership of Nato.

This is not something recent UK governments have broached. The official view, since the EU referendum, has been that we are leaving the EU, but we are not leaving Europe, and we are certainly not leaving Nato. Indeed, the defence alliance, it is suggested, takes on even greater significance for the UK than before, in terms of being part of a bigger grouping and the military contribution it can make.

But – to start with the basics – the sovereignty argument that was used to some effect by the Brexiteers is equally, if not more, relevant to our membership of Nato. Any alliance entails elements of ceded sovereignty. Our nuclear deterrent is independent in name only. Its deterrence effect has also to be gauged in a world where cyber and a host of unmanned weapons are on the horizon.

How do the finances stack up? What do we pay (answer: more than most), and what do we get in return? Once upon a time the answer would have been a cast-iron defence guarantee – the famous Article 5. But what if Trump’s America First turns out not to be an aberration, but a longer-term trend, or future US administrations actually enact that “pivot” to the Pacific?

The reasons for the Brexit vote also have implications for defence. A common view is that Leave voters were nostalgic for Empire; but many more seem to have favoured less, rather than more, international engagement, seeing defence primarily in terms of defending the UK. Would these voters, if asked, regard Nato membership as an asset or a liability? A source of protection or unwarranted danger – as in Afghanistan or deployments close to the Russian border?

All these questions could be posed even more starkly if the EU – without the UK, remember – embarked on developing its own defence capability. It might initially be complementary to the US pillar of Nato, but then, increasingly, become independent. Where would that leave the UK?

As of now, with Nato membership accepted almost unnoticed as a fact of life, UK opinion remains more favourable than not, according to a YouGov poll released for the alliance’s 70th anniversary in April. But the same poll shows support declining in most countries in western Europe, and declining especially sharply in the UK (from 73 per cent to 59 per cent since 2017) and in Germany from 68 to 54 per cent over the same time.

Whether the UK will ever hold a referendum on Nato membership – or indeed on anything else – must be doubtful. The fall out from the EU referendum may have inoculated this country against holding another plebiscite for a very long time. But as Nato celebrates its 70 years and the UK reconfirms its Nato allegiance in the wake of Brexit, there are signs that change could be in the air. A time will come when, if not a referendum, then at least a serious national debate, will need to be had.