This is trivially falsifiable. We didn't nuke Afghanistan after 9/11.
(We did nominally succeed in regime change in the country that didn't attack us, though...)
(We did nominally succeed in regime change in the country that didn't attack us, though...)
It wasn't Afghanistan (as a nation) that directly carried out 9/11. The government did have close ties with Al Qaeda and sheltered it though.
> An attack on American soil could be met with a literally nuclear response against Iran or whoever perpetrated it.
Al Qaeda is in the "whoever" category that you claimed would be met with a nuclear response.