The cascade of machines, arranged in long halls and shielded by concrete and steel, have been central to Iran’s most sensitive nuclear work, and, until recently, largely immune to airstrikes. But this month Israeli warplanes penetrated Iranian airspace and struck multiple nuclear sites,

With Donald Trump mulling whether to send in American bunker-busting bombs to deal a crushing blow to Iran’s nuclear facilities, doubts remain about just how close Iran is to creating a nuclear bomb.

Israel’s military has said the current goal of its continuing campaign against Iran is the dismantling of Tehran’s nuclear and ballistic missile programmes. Iran has been enri