A journey inside the complex mind of Vladimir Putin
In June 2005, Vladimir Putin saw a diamond-studded Super Bowl ring on the finger of Robert Kraft, the owner of the New England Patriots.
Kraft was in St Petersberg for a gathering of business leaders, and the ring was worth $25,000. Putin asked to see it, tried it on, and said: "I could kill someone with this." Then, allegedly, he put it in his pocket, drew his security guards around him, and left the room.
What does this incident tell us about the psychology of the man who rules Russia?