Spread it around at sporting events or in airport terminals. Airport terminals would be the most effective, which almost makes me think they don't have any smallpox. With a vaccination, the carrier wouldn't even have to die to spread it. Walk through the terminal with a concealed dispersion container. Walk out. Then it gets spread all over the country.
No, if it is in an airport then it spreads all over the world. Even to their countries where medical treatment and infrastructure is not very good. They could end up getting more of thier people dead than we have. I really don't think they will try small pox.