PRESIDENT Donald Trump placed the biggest bet of his presidency on the afternoon of May 8th. To the horror of European partners but the delight of such allies as Israel, he pulled America out of the Iran nuclear deal signed in 2015. He acted on a hunch that Iran’s leaders—if only they are subjected to unprecedented economic pain—will break and abandon all manner of hostile activities, from nuclear weapons development to support for terrorism and involvement in the bloodiest proxy wars of the Middle East.

Mr Trump, the consummate pitch-man, sold the move as a dead cert. “This will make America much safer,” a stern and unusually terse president promised as he signed a memorandum re-imposing all sanctions lifted by his predecessor, Barack Obama, and giving foreign governments and firms up to six months to stop buying everything from Iranian oil to carpets or face tough secondary sanctions from his Treasury department. But Trumpian swagger could not quite conceal the multiple risks he is running.

Mr Trump is betting that Iranian leaders are bluffing when they say that the narrow, time-limited nuclear weapons freeze they grudgingly agreed with America and other world powers some three years ago is their best and final offer. “I’d probably say the same thing if I was in their position,” Mr Trump conceded. “But the fact is they are going to want to make a new and lasting deal,” he predicted. When Iran is ready to climb down, he promised to be “ready, willing and able” to talk.

Others wish they shared his breezy assurance. A European diplomat describes weeks of intensive discussions with the White House, asking for a rationale behind this colossal roll of the dice. The president has decided to ask the Iranians for everything, came the reply: for a total, permanent end to nuclear enrichment, to ballistic missile programmes and to its mischief-making in the region. Tiring of promises by allies to fix the Iran deal, formally the Joint Comprehensive Plan of Action (JCPOA), Team Trump has chosen demolition. The president has decided that since the foundations are faulty, it is better to tear the whole building down, Europeans were told.

Mr Trump’s own confidence appears to rest on several pillars. One, his contempt for Mr Obama, and matching conviction that he can improve on any deal reached by his cerebral predecessor. After months of calling the Iran deal of 2015 “insane” and “the worst” Mr Trump—perhaps swayed by the gravity of the moment or the grandeur of the White House’s diplomatic reception room—contented himself with calling the nuclear pact “horrible”, “rotten” and “one-sided”. Flying in the face of all testimony from those involved in the talks from 2015, he baldly asserted that a better, constructive deal “could easily have been struck at the time.”

Briefing reporters after the announcement Mr Trump’s hawkish national security adviser, John Bolton, added some historical shading to his boss’s broad brush-strokes. America had learned a painful lesson a long time ago, said Mr Bolton: that “we only negotiate from positions of strength.” In walking away from the Iran deal and by re-imposing (and quite possibly soon expanding) Iranian sanctions, America is establishing such positions of strength, he explained.

Mr Bolton offered a further bet. Getting out of the Iran deal would prove helpful when Mr Trump met North Korea’s leader Kim Jong-Un, he averred, by sending “a very clear signal that the United States will not accept inadequate deals.”

Mr Bolton denied, sort of, that the administration’s goal is Iranian regime change. Instead he chided Team Obama and other powers for agreeing a deal that only addressed Iran’s nuclear ambitions, and that left uncurbed its support for terrorists and such proxies as Hizbullah and Hamas. To really bring peace to the Middle East, he said: “You really have to go after the whole thing.”

Deep down, hawks like Mr Bolton—echoed by the new secretary of state, Mike Pompeo—do not trust any arms-control agreement that a country like Iran could sign, especially if it is policed by the UN and its inspectors. Asked about public statements from Trump administration officials, including the Director of National Intelligence, Dan Coats, that Iran is in technical compliance with the terms of the deal, Mr Bolton sniffed: “You cannot say that Iran is in compliance unless you are 100% certain that the IAEA and our intelligence are infallible.”

Binyamin Netanyahu, the Israeli prime minister, applauded Mr Trump’s “bold decision” to reject “the disastrous nuclear deal with the terrorist regime in Iran.” Mr Netanyahu has consistently rejected arguments that the JCPOA for all its flaws pushed Iran at least a year away from “break-out” to a nuclear bomb, though his arguments tend to rest on Iran’s general wickedness and years of lying, rather than on a detailed Plan B that would offer greater security.

Finally Mr Trump and his hawkish aides are making a bet about European friends. They are gambling that the governments of Britain, France and Germany are bluffing when they say the current deal is so much better than no deal at all that they will strive to keep it alive, even after their American ally has walked away. In a joint statement Theresa May of Britain, Emmanuel Macron of France and Angela Merkel of Germany noted that according to the International Atomic Energy Agency’s inspectors Iran continues to abide by the deal’s restrictions. “The world is a safer place as a result,” the trio declared, promising to work so that the Iranian public continues to see the economic benefits from their government’s decision to stop building nuclear weapons. Nodding to American demands to make permanent constraints on nuclear enrichment and other activities that can resume after 10-15 years under the JCPOA, the three European leaders agreed that a side-deal is needed to ensure that Iran forever forswears nuclear arms.

Alas, such talk of a side deal fails to satisfy Mr Trump. In theory the president only faced one imminent deadline on May 12th to decide the fate of one tranche of American sanctions, involving dollar-based bank transactions and trading in such products as oil. But after months of heeding calls for patience from some of his most senior advisers, including the defence secretary, James Mattis, and military chiefs, Mr Trump lost patience.

Mr Trump has at a stroke re-imposed every variety of Iran nuclear sanction suspended in the name of diplomacy in recent years. His new memorandum bans new contracts with Iranian entities to buy or sell everything from oil to cars, steel, passenger aircraft or pistachios. Companies and banks with existing contracts have between 90 and 180 days to wind-down their trade with Iran. The only wriggle-room that optimists in Europe can see would involve America granting case-by-case waivers as part of that process.

When it comes to that last punt on European resolve and its limits Mr Trump is probably on safer ground. It is one thing for politicians like Mrs May, Mr Macron and Mrs Merkel to talk stoutly about keeping JCPOA alive and economic benefits flowing. But Iranian ultra-hardliners are ready to charge somewhat-hardliners with foolishly trusting America back in 2015, and to demand the resumption of nuclear work. European companies, meanwhile, would have to be awfully brave to keep trading with Iran and risk their access to America’s markets and banking systems.

“I’ve never gambled in my life,” Donald Trump bragged in 1987, when building casinos was his main claim to fame. “I prefer to own slot machines. It’s a very good business being the house.” A similarly cold-eyed approach to foreign affairs helped him win the presidency. War-weary Americans cheered when Mr Trump pledged to put them first and stop trying to fix an ungrateful world.

That isolationist, calculating Trump was forgotten this week. Inspired by loathing of Mr Obama, and his gut instinct that the Iran deal rewarded a foe and threatened such friends as Israel, Mr Trump has turned high-rolling gambler. If his hunches are wrong, the losses could include a trade clash between America and Europe, a surge in Iranian-backed violence and terrorism and grave damage to the decades-long cause of nuclear non-proliferation. That would be a bet without winners.