This is from my email to Seth Hettena, he stimulated some thinking. I recommend reading his blog.
From this brief description: “The Scorpion and The Frog” I got the impression that the Stinger sales were a diversionary step by the GRU to direct the attention to bin Laden as the future culprit and cover for their own future role in 9/11. This sale could not have happened without them, it is clear. The previous “show” of the “radar guidance system” was a preliminary confidence-building gesture, which tells us that it was them, the GRU, who was interested in these contacts to build a future cover. The episode with publishing the book also looks like their job: to enhance publicity for the future cover. Sater was used then and later as a useful intermediary, probably a man of Mogilevich, who apparently has very close GRU connections.