[aphextron]

>Why would you try to poison someone with no real threat to you and risk him becoming a martyr, using a method that immediately brings you to mind, with a nerve agent that is also strongly linked to you?

They want everyone to know they did it. That's Putin's MO. Everyone knows he did it, and he knows everyone knows he did it. But there's still enough plausible deniability that it would be hard to conclusively prove. And ultimately he has his finger on the world's largest arsenal of nuclear ICBMs, so he knows there's absolutely nothing anyone can do about it. It's the same as the mafia leaving a severed horse head in your bed. It sends a message.