> I don't think we have a better option
I'd love help getting on board with this
If they managed to get enough of their HEU and any reactor spent fuel out of Fordo and elsewhere into locations we don't know about where they happen to have previously built backup facilities then they could have them very quickly. Hopefully a) they didn't build backup facilities, and b) didn't get a change to spirit away the materials w/o us noticing.
If commercial satellite photography can keep an eye on the movement of trucks in this area, it's probably safe to assume that spy satellites can too.
20 years is reasonable time to rebuild
If we fail, there's still the hope that other commenters here are right, and Iran isn't intent on using them offensively. If so, then Iran itself will be safe from this sort of attack.
... but it will also be clear to every other that the only way to be secure from Western military intervention is to possess nuclear weapons. There will be a precedent of a country acquiring them despite Western demands and surviving. This will lead to a world where proliferation is rampant, but not necessarily one where their use is no longer taboo as it is today.
Like North Korea?
And like Ukraine (conversely).