FAE or a B61 Mod 11 would be a great pre-strike on said hardened targets...... then cluster bomb the bejesus out of the remaining soft targets etc etc ...
Just my opinion.....:o)
FAE would do nothing. Roast everything above ground, yes, but subterranean impact would be nil.
B61 Mod 11 would be perfect. Problem is, I doubt Israel has any, so they’d have to rely on mundane nuclear ground strikes.