TEHRAN’S grand bazaar, a weathervane of politics, is on strike again. Shutdowns there foreshadowed Iran’s 1979 revolution. In 2012 they pushed the government into talks that eventually resulted in a deal, signed in 2015, that restricted Iran’s nuclear efforts in exchange for sanctions relief. And Donald Trump’s pull-out from that deal on May 8th drew an instant reaction from traders, who sense something ominous. “Tehran feels like it did before...1979,” says Pejman Abdolmohammadi, an Iranian lecturer at the London School of Economics.

Iran’s business world was already glum. America’s continued curbs on dollar transactions had muted the effect of the lifting of global sanctions in January 2016. But now, merchants say, America is moving from containing the regime to trying to change it. Mr Trump has told firms worldwide that they have three to six months to cut ties with Iran or face sanctions, too. Oil exports, which rose as a result of the deal, are already falling. Maersk, the world’s largest shipping line, no longer takes orders for Iranian oil. South Korea has cut oil imports from Iran by 40%.

President Hassan Rouhani, who struck the nuclear deal, is struggling. His officials have shut currency exchanges, chased money-changers off the streets and fixed the exchange rate. But most of the foreign reserves needed to calm the market are abroad, and America is making it hard to repatriate them. On May 15th America’s Treasury called the governor of Iran’s central bank a financer of terrorism. The Paris-based Financial Action Task Force reports soon on whether Iran’s banks heed anti-terror and money-laundering rules. This “could knock Iran off the financial system”, says a diplomat.

Middle-class Iranians are sullenly cancelling foreign trips. But they always disliked the regime; worse for the clerics is the loss of their base. In December the urban poor in the provinces took to the streets, denouncing theocracy. Despite efforts to quell it, industrial action rages on. Merchants in other bazaars have also gone on strike, as have some teachers. Officials have blocked Telegram, a popular social-media app. Young Iranians are furious.

The regime is resilient, some say. Its economy is the world’s 27th largest. It pumps 3.8m barrels a day of oil, and it is good at smuggling. Muhammad Javad Zarif, the foreign minister, has taken to Beijing and Brussels his ideas for dodging American curbs. They include creating a bank trading only in euros, and depositing Iran’s oil takings in Europe’s central banks. But getting Europeans to forfeit American markets will be hard.

Meanwhile, hardliners have Mr Rouhani in their sights. They say his deal gave up a lot for little reward. With their grip on the judiciary, the security forces and some state concerns, they are squeezing him. They have chased an adviser of his back to London and arrested many dual nationals. Some see in sanctions a chance to resume smuggling. If regime change comes, it could consist of a coup mounted by these dark and well-connected characters.