NATO is meeting this week at a moment of very real crisis. Donald Trump’s second presidency has thrown the globalised world order into chaos. Old certainties are being torn up. Trump threatens to abandon even the impression of a collective approach to projecting US power through stable alliances and joint institutions.

His sudden decision to attack Iran is of course the main case in point. He is unilateral and unpredictable. Soft power is out, economic and military muscle is all that counts, and Trump will wield them both ruthlessly and with cold calculation in US interests.

The implications for Nato are grim. Nato was set up in 1949, at the behest of Clement Attlee’s Labour government, as a way of aligning the efforts of the US and the western European powers at the start of the cold war. In reality it was always a means to ensure US dominance of Europe. It served a number of complementary purposes for the big winner of the second world war. In the words of the British Lord Ismay, its first secretary-general, it was a means “to keep Russia out, the Americans in and Germany down.”

During the cold war the US and its allies co-ordinated soft and hard power to ensure that what was called the communist threat was rolled back and that the western European powers accepted US leadership. Eventually the plan worked. By the end of the 1980s, the US-led arms race with Russia brought the economies of Russia and its satellites in eastern Europe to the point of collapse.

For all the celebrations in Western capitals, the aftermath was an awkward time for Nato. With the collapse of Russian power, its European leaders had to try to prove its continued relevance. As US concerns tilted away from Europe, Nato had to show that it had “out of area” capabilities. At the end of the ’90s, Tony Blair was the main champion of the Nato-led attack on Serbia. Nato then took control of the disastrous 20-year occupation of Afghanistan and in 2011, France and Britain were the key drivers of the Nato attack on Libya that ended in regime change and turned the country into a failed state.

In so far as there is a Trump military plan it is to settle issues in eastern Europe and the Middle East in order to free up US forces to focus on the big challenge to US global hegemony, China. China is approaching economic parity with the US, and it is arming faster than any other country on Earth. For Trump, and indeed most of the US Establishment, there is a window of opportunity to tame China before it becomes a deadly threat to US imperial dominance.

Trump’s plan is crumbling. Regional conflicts in the Middle East and eastern Europe, triggered largely by recent Western interventions and expansions, are proving stubborn. It is in these theatres of war that rivalry with rising China and its allies are in fact being played out. As he pursues his attack on Iran, Trump’s talk of being the peace president looks more and more ridiculous. His frustration is only increasing his inclination to act ruthlessly and if necessary, alone.

So where does this leave Nato? US unilateralism and naked aggression are causing the European powers deep anxiety and embarrassment. They fear being sidelined and they are worried about Trump’s unpredictability.

Over Iran they have half-heartedly called for restraint on both sides, but in reality they have no independent strategy, and they are going along with the absurd notion that Iran is the big threat in the Middle East even though Israel has been causing the carnage.

The situation is exposing in the most brutal way that Nato has always been a vehicle for US power, just at the time when the US is at its most belligerent and unpopular around the world.

The response of the European leaders, led initially by Sir Keir Starmer, has been to scramble to rearm across the continent. The claim is that this is for security purposes and to assert military independence. In reality, the European leaders are doing exactly what Trump wants. And they are doing it to try to signal their continued relevance, to show Trump and the US ruling class that Nato still has clout and that they will be useful partners in whatever the wounded superpower does next to try to maintain its dominance in the world.