I say BS. Those shiny chimneys and plants they show on TV every day are all in the open and look awfully vulnerable to me.
First:
the western intelligence agencies are not necessarily convinced that Iran is actually trying to build a bomb.
mostly their consensus appears to be That Iran is trying to create Break out capacity so that they can build a bomb within a year's notice if they so decided.
Let's assume for a moment that the west can not live with an Iran that has Nukes (That's a big assumption)
Let's also assume that the west can not live with an Iran that has Breakout capacity (a bigger assumption.)
Thus far (last 14 years or so) the west has manged to monitor and manage Iran's nuclear program
using diplomacy.
You have to understand the mindset of western planners.
The western governments have to comply with various mandates such as implications on world economy, public opinion, strategic considerations, ....
The middle eastern point of view is life has no value and economic welfare of citizens is of little concern.
That's why from a sane American point of view using Military Power so long as there appears to be diplomatic room to run will be counter-productive.
Any Military Strike has certain risks however small those risks may appear to be.
But the more important implication of military strikes are that it will create an imbalance in a region that as it is has difficulty reaching an equilibrium.