When it first broke I thought it was a hoax, but it gets curiouser and curiouser. Who in the world is using an absolutely traceable, absolutely nuke weapons related poison to kill a former Soviet spy? Putin? If he did something crazy is going on. Let's look at Putin as prime suspect.
He has cause, as Litvinenko was a formidable critic of the gargantuan corrupt criminal enterprise that is Putin's Russia. But if he decided to whack him why use a poison that leads directly to a nuclear laboratory. Did they think it was undetectable? Even so, why not just shoot him, or have him mugged to death? It smells like they were sending a message to other critics reminding them that Putin used to operate in the basement at Lubyanka prison. There are plenty of other folks out there with dirt on Putin, but it's not hard to see why the possibility of having your guts shredded by radiation might make you reluctant to air any concerns about Vlad the Poisoner.
If it's not Putin things get crazy fast. That means someone other than him has access to the nuke weapons labs and has lifted Polonium and who knows what else. There is plenty of seriously heinous stuff in closets all over the former Soviet Union including nukes, chemical weapons, bio badness and if this is the first instance of that stuff coming into play we are in deep shite. Bad enough that AQ Khan was passing nuke secrets around, the stuff in the former Soviet Union was top of the line, almost as good as our stuff.
I almost hope it is Putin just because the second scenario is incredibly scary. More at Hot Air