1)The protection money theory:
A former Clinton administration official has claimed-and US intelligence sources concurred-that at least two Saudi princes had been paying, on behalf of the Kingdom, what amounted to protection money since 1995. "The deal was," the former official said, "they would turn a blind eye to what he was doing elsewhere. 'You don't conduct operations here, and we won't disrupt them elsewhere.'"
American and British official sources, speaking later with Simon Henderson-Baker fellow at the Washington Institute for Near East Policy-named the two princes in question. They were, Henderson told the authors, Interior Minister Naif and the minister of defense and aviation, Price Sultan. The money involved in the alleged payments, according to Henderson's sources, had amounted to "hundreds of millions of dollars." It had been "Saudi official money-not their own."
The Eleventh Day by Anthony Summers and Robbyn Swan
pg. 394
2)They don't like us theory:
At the State Department, the director of the Office of the Coodinator for Counterterrorism concluded that the (Bin Laden) relationship with some royals went way beyond recreational pursuits. "We've got information about who's backing Bin Laden," Dick Gannon was saying by 1998, "and in a lot of cases it goes back to the royal family. There are certain factions of the royal family who just don't like us."
The Eleventh Day by Anthony Summers and Robbyn Swan
pg. 394
The media likes to talk of collective country agendas as if US and Saudi leaders were all of the same page with their citizens. Like the US public has any idea WTF Bush and Bandar talked about in secret. Look at the invasion of Iraq. How was that in the best interests of the US public? What we had was a small faction of insiders who manipulated the public into supporting their policy agenda. Perhaps a similar scenario played out with US and Saudi insiders in regard to 9/11.