When has IRI ever acted with common sense?
Trump’s own military advisers reportedly doubted their ability to penetrate Fordow, and some strongly advised against attempting it. At least, that’s the version of events we were told, though it’s possible the narrative was meant to throw IRI off balance.
Still, it’s entirely plausible IRI believed it was safer to keep the highly enriched uranium hidden rather than risk exposing it during transport. What also seems likely is that they never anticipated IAF conducting sorties over the entire country for twelve consecutive days let alone the US joining the bombing campaign.
And maybe the miscalculation came from their own propaganda. After years of threatening to wipe Tel Aviv and Haifa, and leveling all US bases in the region, insisting no one would dare touch them, they might have started believing their own myths of invincibility.