The stories have been about rows here and spats there, who thinks what of whom.

But there is a lot at stake in this week’s Nato summit in London, not least the purpose of the alliance and its very future. Columnists are exploring more.

Financial Times

Ivan Krastev is old enough to have lived on what for Nato was the wrong side of the Iron Curtain.

So the Bulgarian has more reasons than most to understand what the North Atlantic security treaty is, or was, all about.

But Mr Krastev reckons Europeans are re-imaging their security without America. And not just because of Nato-Sceptic Donald Trump. The old world, he think, no longer quite believes it will always have an ally to their west.

He wrote: “European policies toward the United States have been oscillating between grandstanding about our ability to do everything on our own and panicked pretending that everything is as it used to be. See, for example, when President Emmanuel Macron of France recently proclaimed that Nato was experiencing “brain death” and Chancellor Angela Merkel of Germany quickly responded by insisting that “NATO remains vital to our security.”

That is what generates the headlines. But, adds Mr Krastev, “beneath the surface, a new European consensus on trans-Atlantic relations is emerging and it represents a huge change.

“Until recently, most European leaders’ hopes were bound up with the outcome of America’s presidential elections. If Mr. Trump were to lose in 2020, they believed, the world would somehow return to normalcy.

“But they have finally started to realize that a proper European Union foreign policy cannot be based on who is in the White House.”

Foreign policy wonks in Europe, Mr Krastev suggests, are now also fretting about Democrats.

He wrote: “The spectre of Russian subversion did not provoke a bipartisan allergic reaction. When Trump voters were told that President Vladimir Putin of Russia supported their candidate, they started admiring Mr. Putin rather than abandoning Mr. Trump.“For the past 70 years, Europeans have known that no matter who occupies the White House, America’s foreign policy and strategic priorities will be consistent. Today, all bets are off.”

The Guardian

For Rafael Behr, the tough Nato conversations cannot be separated from Brexit.

First, because European allies see Brexit - along with Trumpism - as “wrecking balls” for the old rules-based system of Western allies.

Second, because Brexit weakens the UK in Nato.

He explained: “Westminster has treated Brexit as primarily an economic debate or a cultural faultline, when it is a strategic choice before it is either of those things.

“To surrender a seat as one of the three steering powers at the EU’s top table has a substantial cost in power and influence.

“It will not be comfortable for a country thus diminished to spend the coming decade in supplicant stance, knocking on doors, waiting in antechambers, taking rules when it once wrote them.”

For Behr anti-imperialist Jeremy Corbyn - who is instinctively anti-interventionist - is just as cuplpable as Boris Johnson.

He continued: “That is true whether you look at it from the left or the right. It continues to be true even when the only two men who might be prime minister after this election collude in pretending otherwise.

The Scotsman

Can Nato survive contact with Trumpism? That is the question for Martyn McLaughlin in The Scotsman.

He asks: “How far Mr Trump can bend Nato to his will before it breaks.

“He has demonstrated no desire to promote or reinforce the alliance’s underlying principle of collective defence, and at a time when a resurgent Russia is gaining footholds in the Middle East and waging complex disinformation campaigns - and worse - on western countries, the old conventions no longer seem fit for purpose.

“To change that and up its game, Nato requires cohesion - or at the very least, leaders who recognise the importance of multilateral diplomacy, and who treat autocrats with contempt instead of giddy subservience. Such qualities are sorely lacking in Mr Trump, who has done more than any other US president to undermine our shared security and values.”

Mr McLaughlin, however, recognises that the American leader is “not the the only demagogue in statesman’s clothing brandishing stones inside Nato’s glass house”.