It was about five years ago that Iran's expatriates finally gave up hope. Far from a transient aberration, they realised that the evil, vicious regime they loathed so much was here to stay. Until then, many members of the large Iranian communities in London or Los Angeles remained surprisingly upbeat. It was as if they were clinging to the hope that it would all be over by Christmas, or rather Naw-Ruz, the Persian new year.

They were quick to share anecdotes from a relative "back home" about why democratic pressure was building, or to relay dubiously upbeat claims made by pundits on US-based Farsi-language satellite TV. Yet, slowly but surely, even the most Panglossian were forced to admit that real change wasn't on the horizon. The Green movement and the 2009-2012 protests achieved nothing. The victory of the so-called reformist Hassan Rouhani was a non-event for minorities and dissidents, who continue to be persecuted.

Barack Obama's nuclear deal in 2015 merely gave the regime a spring in its step, freeing up vast amounts of cash to ramp up its destructive meddling in Syria, Lebanon and Yemen without improving ordinary Iranians' lives. The result was the furious anti-regime demonstrations earlier this year - and they, too, were savagely put down.

Iranian society is now in such a state of ruin that it will take decades of freedom to heal. It's not just the grossly mismanaged economy that is in the doldrums. The real crisis is social: suicides, extraordinary levels of drug addiction, a mental illness epidemic, an unhealthy obsession with plastic surgery, and youth in the grip of an extreme alienation from everything bar materialism.

But none of this matters to the regime, whose sole purpose is to survive for as long as possible and to export its ideology. Until recently, it had been playing a blinder, leveraging the West's willingness to appease its enemies to its advantage, and using the nuclear deal to fill the post-Iraq void in the Middle East. Its actions in Syria, where it supports Assad, are tantamount to aiding and abetting war crimes; its funding of Hizbollah and Hamas, and its decision to locate tens of thousands of missiles in Syria and Lebanon, mean that it is now the world's number one terror state.