As noted, in 2018, Trump breached the agreement and put Iran under a financial and economic blockade of unprecedented severity. As he intended, these moves crashed the Iranian economy and created public unrest. The US strangulation of the Iranian economy did not accomplish what Trump was aiming for. It did not cause the government to collapse. It did not make Ayatollah Ali Khamenei come begging to Trump for a photo op and a new treaty. It did make people in Iran angry, so that there were some vigorous and sometimes even violent price protests, but those did not turn into politics. Random people in various cities torching gasoline stations doesn’t affect the political scene unless they organize around their grievance and engage in party politics. They didn’t.