LONDON – President Donald Trump’s warning that NATO faces a “very bad future” unless its member states help the US open the Strait of Hormuz to oil shipments confirms Europe’s worst nightmare: that, after launching the offensive against Iran without consulting his allies, Mr Trump will then turn to the Europeans to help Washington deal with the consequences of his war.

“It’s only appropriate that people who are the beneficiaries of the strait will help to make sure that nothing bad happens there,” Mr Trump told London’s Financial Times daily, arguing that, unlike the US, Europe is heavily dependent on oil from the Gulf.

“If there’s no response or if it’s a negative response, I think it will be very bad for the future of NATO,” the US President added.

Mr Trump’s warning to the Europeans came after he launched a similar appeal to Australia, China, Japan and South Korea to join in what he referred to as a “team effort” to open the Strait, through which 20...