FEATURE | NATO faces existential test as Trump fumes over lack of Iran help

The NATO alliance has in recent years survived existential challenges - ranging from the war in Ukraine to multiple bouts of pressure and insults from US President Donald Trump, who has questioned its core mission and threatened to seize Greenland.

But it is the US-Israeli war with Iran, thousands of miles from Europe, that has nearly broken the 76-year-old bloc and threatens to leave it in its weakest state since its creation, say analysts and diplomats.

Trump, enraged that European countries have declined to send their navies to open up the Strait of Hormuz to global shipping following the start of the air war on February 28, has declared he is considering withdrawing from the alliance. "Wouldn't you if you were me?" Trump asked Reuters in a Wednesday interview.

In a speech on Wednesday night, Trump criticised US allies but stopped short of condemning NATO, as many experts thought he might.

But combined with other barbs aimed at Europeans in recent weeks, Trump's comments have provoked unprecedented concern that the US will not come to the aid of European allies should they be attacked, whether or not Washington formally walks away.

The result, say analysts and diplomats, is that the alliance created in the Cold War that has long served as the basic fabric of European security is fraying and the mutual defence agreement at its core is no longer taken as a given.

"This is the worst place (NATO) has been since it was founded," said Max Bergmann, a former State Department official who now leads the Europe, Russia, and Eurasia Programme at the Centre for Strategic and International Studies in Washington.

"It's really hard to think of anything that even comes close."