would be "very bad for the future of Nato" – implies an understanding of the alliance's purpose that has already raised eyebrows. "Nato was created as a…defensive alliance," Gen Sir Nick Carter, former Chief of the Defence Staff, told the BBC on Monday. "It was not an alliance that was designed for one of the allies to go on a war of choice and then oblige everybody else to follow," he said. "I'm not sure that's the sort of Nato that any of us wanted to belong to." Coming from a president who only two months ago was making strident claims to Greenland, the sovereign territory of a fellow Nato member, there's more than a little irony in his latest remarks. This perhaps helps to explain why some responses have been fairly blunt.

In Germany, a government spokesman said the war with Iran "has nothing to do with Nato", while the Defence Minister Boris Pistorius seemed to pour scorn on the idea that Europe's modest navies could make a difference. "What does Trump expect from a handful of European frigates that the powerful US navy cannot do?" he asked. 

"This is not our war. We have not started it." But none of this should hide the fact that there's now an urgent, and growing, need for a solution to the crisis in the Gulf. Iran's effective blocking of the Strait of Hormuz – except for a handful of vessels carrying its own oil to allies like India and China – has left western governments scrambling to find a solution. It may be a crisis triggered by Donald Trump's decision to go to war, but it's one that needs to be fixed quickly, before the impacts on the global economy get any worse. But it's already clear that there is no quick fix. (BBC)