ONCE again, through gritted teeth, President Donald Trump has granted a stay of execution for the Iran nuclear deal brokered by his predecessor, Barack Obama. But this is the last time he will do so, he announced on January 12th. This fresh reprieve for the Iran agreement—which on the campaign trail Mr Trump called “the worst deal ever” and promised to tear up—highlights the dilemma faced by America’s closest allies, notably in Europe.

A big part of Mr Trump's climb-down is due to public pressure from allies such as Britain, France and Germany, whose governments made clear that they think this deal is the best available; they would not join Mr Trump in negotiating a replacement if he blows this one up. But even as he swallowed his pride and signed off on an extension for the agreement for a further 120 days, the president said that he would still walk away from the deal if it is not toughened by allies and by Congress, and soon.

In part as a face-saving measure, Mr Trump imposed new sanctions that target 14 Iranian individuals and entities, including the head of the Iranian judiciary, Sadeq Larijani, whose brother is the speaker of parliament.

In a statement Mr Trump called his decision to keep the deal alive a “last chance”. In the absence of an agreement in which Congress and European allies six “significant flaws” in the pact, “the United States will not again waive sanctions to stay in the Iran nuclear deal,” he declared.

European allies fear that there are few realistic prospects of the Iranian regime agreeing to Mr Trump’s most urgent demands—namely, to make the bargain permanent rather than time-limited and to link fresh concessions, for instance involving inspections of Iranian nuclear sites, to “triggers” that would otherwise automatically cause sanctions to “snap back”. Ultimately Mr Trump would like an agreement that ranges well beyond the narrow question of nuclear arms so that it covers a wide array of provocative Iranian conduct in the Middle East. Europeans and other world powers believe that it was only the narrowness of the original deal that secured Iranian co-operation in 2015. As a result, a geopolitical crisis has been postponed, but not avoided.

To put it plainly, European allies have discovered that with a lot of pushing they can stop Mr Trump from pursuing what they consider disastrous foreign policies. What they cannot do is secure for him the concessions that he sees as necessary to make better, properly “America First” policies.

Mr Trump’s allies are learning how to play defence with this most alarming of American leaders. They have yet to figure out how to work constructively with him, to shape the sort of world order that is to his tastes. That—more than any urgent headlines generated by the president saying he does not want people from “shithole countries” moving to America—is the dilemma faced by his allies.

In technical terms, Mr Trump grudgingly agreed to continue to suspend economic sanctions on Iran’s central bank and on oil exports, which were first lifted to reward Iran for freezing nuclear weapons work under an agreement reached with America and other world powers in 2015. Thanks to legislation passed by a sceptical, Republican-led Congress during the Obama era, the legal waivers allowing Iran sanctions to be lifted must be renewed every several weeks. This was the third time that Mr Trump was persuaded by his most senior national security officials and the leaders of allied governments that the costs of blowing up the deal outweigh the benefits.

As the deadline to approve a fresh set of waivers drew near, the gulf between Mr Trump’s worldview and those of his aides and allies was freshly exposed. Iran has been convulsed by anti-government protests for since late December, leading to the deaths of at least 21 people and thousands of detentions and arrests. The sight of the protests reportedly made the president more reluctant than ever to extend the life of the nuclear deal, which he scorns as an appeasement of an Islamic regime that funds terrorist groups, armed militants and rebel factions across the Middle East and wider region, while pursuing ballistic missile programmes that put Israel and other American allies in harm’s way.

However Mr Trump’s own national security staff and foreign allies take away a different lesson from those same protests: that walking away from the Iran deal now could play into the hands of the hard-liners atop the clerical establishment that runs the country. The pressure from allies has been unusually public. President Emmanuel Macron of France telephoned Mr Trump to reaffirm his country’s determination both to see the Iranian deal “strictly enforced” and to see “all of its signatories abide by it.”

In an apparent show of solidarity with relative moderates in the elected Iranian government, European foreign ministers in Brussels met their Iranian counterpart, Mohammad Javad Zarif, on Thursday. Though the Europeans pressed Mr Zarif about Iranian trouble-making in its backyard, they also issued ringing declarations about the continued worth of the nuclear deal, saying in the words of Boris Johnson, the British foreign secretary, that it “makes the world safer” and that nobody has so far produced a better alternative. Late last year, in equally striking comments, the German ambassador to Washington warned that tearing up the nuclear deal when Iran is abiding by its requirements risked sending a dangerous message to North Korea, should a nuclear pact with that country become possible.

Assuming that Mr Trump is not bluffing, that gap of perceptions must either be bridged soon, or his America First policy towards Iran will look more like America Alone.