This is such a BS story. Kraft kept quiet at that time hoping for a business opportunity thru soviet largesse in return for a gift (or theft) of the SB ring. Looks like the opportunity did not arise. So why is the story coming out now?
One reason could be the steadfast support of Syria by Russia. Just yesterday, the US decided to support the syrian rebels. And then this story is posted in a Murdoch mouth piece. Kraft is known to be quite sympathetic to the Israeli cause - this could be his contribution to discredit Putin.
And everything was fine until Putin regifted the ring to Assad.