As the US weighs joining Israel’s assault on Iran, questions are mounting over whether such an intervention could trigger regime change in Tehran – an outcome that risks splintering the country and sending shockwaves across the region.

Trump had hoped to strike a deal to stop Tehran developing a nuclear weapon, but the latest round of talks was cancelled in light of the recent escalation in hostilities. Last year, Iran and Israel launched a number of air strikes against each other in April and October - though Israel's strikes last year were not believed to have been as wide-ranging as its current operation.