Russia's going to launch an ICBM full of smallpox at us!!! Or not...

I find it somewhat ironic that the eradication of a disease can cause it to become a threat later down the road because someone else kept cultures of the pathogen responsible for that disease. To me, it seems almost childish that Russia would do such a thing. If they were indeed to launch this ICBM full of smallpox at us, it would no doubt be the beginning of World War III (if it hasn't begun already). It seems like the reason for all of their smallpox that they're holding on to is a relic of the cold war - maybe they want something with which they can threaten us; something they have that we don't. I mean, let's face it, the US and Russia have not always been the best of friends.
Something else to consider is the fact that if they unleashed smallpox on our major cities, unless all travel and shipping was cut off from North America, smallpox would no doubt spread to the rest of the world - ironically including Russia. And they probably don't also have a stockpile of the smallpox vaccine, so I don't think this is anything to really worry about.
And what if something were to happen and smallpox were to get out in Russia where ever they are storing all of this? I don't really think that keeping smallpox as a weapon for bioterrorism outweighs the public health risks of keeping the pathogen when the vaccine is not made at all due to the fact that the pathogen has been absent from society for years.