Donald Trump is weighing in on the future of the North Atlantic Treaty Organisation (Nato), a topic about which he admits to knowing little and on which he is — not for the first time — spectacularly wrong. But he isn’t wrong to pose the question of whether the alliance is now obsolete.

The case made for maintaining Nato has often been woolly. On Monday, President Barack Obama said that the alliance remains “the lynchpin, the cornerstone of our collective defence and US security policy.”

It was a tacit riposte to Trump. The unaddressed question is: how?

At various times since the collapse of the former Soviet Union, Trump might have found himself in very knowledgeable company asking that question.

In 1998, George Kennan, the architect of the US containment strategy during the Cold War, argued against expanding the alliance into the former Warsaw Pact countries, calling it a tragic mistake.

“Don’t people understand? Our differences in the Cold War were with the Soviet Communist regime,” not with Russia, said Kennan. Russian leaders, then and now, agreed.

Trump’s sentiments also would have been in line with those of former US Defence Secretary Donald Rumsfeld a few years later. Rumsfeld wasn’t that interested in Nato as a consensus-based alliance, brushing off its declaration of Nato’s Article 5 collective defence clause after 9/11. He wanted instead to form ad hoc coalitions of countries willing to sign up to particular US policies, starting with the invasion of Iraq.

Nato itself seemed for some years to be searching for a new role as it talked about needing to, as former US Senator Richard Lugar once put it, either “go out of area or go out of business.”

Alliances do generally have to stand against something if they are to survive, and many have argued that terrorism wasn’t a big enough threat for Nato to unite against. The US scholar of international relations Kenneth Waltz predicted Nato’s eventual demise this way:

“Europe and Russia may for a time look on Nato, and on America’s presence in Western Europe, as a stabilising force in a time of rapid change. In an interim period, the continuation of Nato makes sense. In the long run, it does not.”

Europeans, he continued, “will have to learn to take care of themselves or suffer the consequences. American withdrawal from Europe will be slower than the Soviet Union’s. America, with its vast and varied capabilities, can still be useful to other Nato countries, and Nato is made up of willing members. Nato’s days are not numbered, but its years are.”

Waltz saw the bipolar Cold War world as an historical anomaly. Once it was over, he thought the world would inevitably return to its natural anarchic state, characterised by shifting alliances in search of a balance of power. This was Europe before 1949. Russian President Vladimir Putin thinks the same way. So does Trump, to the extent he has thought any of this through.

But things have changed since Russia annexed Crimea in 2014. Eastern Europeans, who never bought Kennan’s belief that the threat from Moscow ended with the collapse of communism, foresaw a return to pre-communist, imperial Russian impulses. Now they think their fears have come true, giving Nato a renewed sense of purpose. Threats from the Middle East also have come closer to home for Europeans, who have turned to Nato for help with the national security threat posed by the refugee crisis.

And Nato isn’t just a defensive alliance to deal with external dangers; it can help defuse tensions between alliance members. Having witnessed a brawl between thousands of Hungarians and ethnic Romanians in Transylvania 1990 that left six dead and hundreds wounded, I’m pretty sure former Yugoslavia isn’t the only place in post-Cold War Europe with the potential for conflict.

Nato members have, finally, begun to reverse declines in defence spending. The US pays 22 per cent of Nato’s roughly $2.3 billion (Dh8.45 billion) common budget (a reasonable share given that the US accounts for 50 per cent of total alliance GDP). It continues to shoulder far too much of actual spending, but dissolving the alliance makes sense only if the US can afford to walk away from European commitments. It can’t.

The US has too much at stake in the transatlantic alliance: $700 billion in mutual trade in 2014, almost 60 per cent of each other’s foreign direct investment stocks, and a strategic interest in Europe as a power base.

An atomised Europe detached from its alliance with the US, like that proposed by Trump with such insouciance, would be less stable and more dangerous than the Europe we have known. As the US discovered in two world wars, it’s hard to stand aside when things go wrong.

If any US leader wants to encourage it, they should think hard about why it is that the only supporters for the idea in Europe are the likes of Putin in Russia and right-wing ultra-nationalists, such as Hungary’s Jobbik party. Then he must ask himself, do these people have US interests at heart?

— Washington Post

— Marc Champion writes editorials on international affairs for Bloomberg View.