SIX months after the last round of protests over their country’s anaemic economy, Iranians are at it again. But unlike the demonstrations in December, which began in the provinces, the latest unrest erupted in Tehran’s bazaar on June 25th and spread from there. Anger is growing over rising prices, the plunging value of the Iranian rial (see chart) and the cost of foreign adventurism.

The regime looks worried. Security forces fired tear gas to disperse crowds that gathered at parliament’s gates. Ayatollah Sadeq Larijani, the conservative head of the judicial system, threatened those “who disturb the Islamic economy” with execution.

President Hassan Rouhani, a moderate, seems stumped. Instead of the bountiful foreign investment he promised would come from compromising with America, he is reeling from what he calls President Donald Trump’s “economic war”. The value of the rial on the black market has fallen by over half since Mr Trump took office in January 2017, particularly since May, when America withdrew from the deal it and five other powers signed with Iran in 2015. It had lifted sanctions in return for restrictions on Iran’s nuclear programme. In August America will reimpose curbs on Iran’s purchase of dollars and sale of gold; it also wants a full ban on oil sales.

Mr Rouhani won an election last year, but he is challenged by hardline clerics and the Islamic Revolutionary Guard Corps, the regime’s military arm. Members of parliament seek his impeachment. While protesters cry for the restoration of the monarchy, regime insiders mull a military takeover. In its 40th year, Iran’s theocracy looks in poor health.