If there were an ‘accident’ at an Iranian facility, would their pride even allow them to reveal that it happened?
The threat is existential - Israel will not sit and do nothing.
I don’t have the link, but I have seen reports that Israel has ALREADY STRUCK.
Iranian nuke and missile facilities keep mysteriously blowing up. It could be Mossad agents on the ground, third parties like the Kurds, or some kind of very sophisticated micro-UAV.
BTW, I contributed to the micro-UAV work over 20 years ago. DARPA has some the size of a hummingbird that actually look like the bird.
As for payloads, there are explosives with a lot more oomph than C-4 in our arsenal. They are tricky; I saw a lab demolished by 10 MILLIGRAMS of an experimental explosive once. Lab tech survived but lost an arm.