<The material was vetted by a vetted source legally>
Really? What is the motive behind it? With whose permission, Bezos himself? That would be legal then.
Blackmail, pure and simple. They want (they meaning Trump himself and Dave Pecker, President of The Enquirer) Bezos to stop his paper's investigation of the murder of Khashoggi. The Enquirer always does Trumps bidding, ie; publishing unflattering stories about Hilary, Ted Cruz, and so on. I wouldn't be surprised if it is found Trump had already known about the planned murder.