Who was in the Khobar Towers, and what did they do ?
Successfully answering that, will tell you all you need to know about who was actually ultimately behind it.
Well, it was American servicemen.
The fact that he attacked American servicemen advertises Osama's beef against "infidels" being present at all in the Arabian Peninsula, which together with Israel/Palestine and the bordering Arab countries constitutes the Hijaz or "Holy Land" as the Arabs see it, and which the Wahhabi extremists want to make into a "no-go" area for people who aren't Moslems themselves. Whereas under previous Saudi princes, foreigners were allowed to be in Jeddah and the Persian Gulf cities, and Riyadh, and only Mecca (and I don't know about Medina) were the "no-go" cities.
Thus the idea of excluding "infidels" from the entire Holy Land and the Arabian Peninsula resurrects a policy last implemented by the Seljuk Turks after the Battle of Manzikert, which exclusion outraged Christians and led directly to the Crusades -- hint, hint. But Bin Laden's purpose beyond outbidding his own Saudi government for control of the shrines as part of his drive to replace the House of Saud with a Wahhabi extremist government ("Islamic republic"), is to convene a greater war with the West. So one purpose feeds the other as well as itself. Hence his consistent use, partly from convenience in the Khobar Towers case, of peninsular Arabs and Egyptians to attack Americans in Arabia, in Arabian waters, or in America.
It is conversely in our better interest to pour oil on waters, and cool sprays of water on flaming oil, the better to do all things which erode the imposture and impair the leadership mojo of people like Osama Bin Laden and the wretched hater-theorist, Ayman Zawahiri.