Except it wasn't eradicated. It's still stored at the US's Fort Detrick, and in Russian and Chinese bioweapons facilities, too be released as a bioweapon, now that no one has natural immunity anymore.

If you don’t keep it then the first time you’ll get to study it will be when the first bodies are recovered from your cities.

Coincidentally, that would be the first time it would be urgent to study.

It would be a pretty shoddy bioweapon considering you can't really target it and vaccines are available.

Maybe Russia or China are funding anti-vax idiots in the US so that it only affects America :-D

Most people aren't vaccinated for smallpox, and only a very small amount of vaccine is even produced, mostly for medical and military people. Targetting is easy, here's your blanket while the power is out...