Bin Laden the elder was close to the Saudi royal family, especially Faisal. The Kingdom isn't a 'government' in our sense. I'd wager someone within the Kingdom at least knew of OBL's plans to attack on 9/11---if they didn't outright aid him.
The Bushes were close to the Saudi royal family. Barbara Bush called the prince "Bandar Bush."
"...the ashes of the Twin Towers are still smoking. Barely a plane is moving over America. The Federal Aviation Authority has ordered a massive shutdown. Yet what's this flitting from Tampa to Dulles to Boston? Why, just a specially chartered jet picking up holidaying Saudis, including many notable scions of the family bin Laden.
Hearts for transplant can't go by plane; Bill Clinton's in Australia and can't get home. But a 747 filled with rich Saudis has no such problem. They're off to the desert kingdom in the blink of an eye and bleep of some exalted pager. How on earth can this possibly be?
Well now... some 35 years before, a good old Texas boy called James Bath was living in Houston and peddling used aircraft. He happened to sell one, an F-27 turboprop, to a couple of young Saudi mates: Salem bin Laden, heir to a massive construction group fortune, and Khalid bin Mahfouz, heir to the National Commercial Bank of Saudi Arabia. The lads came to fancy Houston, its lifestyle, its girls (and jetsetting around). They put down a few roots; they wallowed in a sudden gusher of petro-dollars; they - and many other Saudis - started to do what comes naturally: cultivate politicians, spread largesse, nurture a little influence. Over a quarter of a century, some $860 billion of Saudi money came flooding into the US and such influence followed naturally.
Meanwhile, a ripe cast of characters gathers. Here's Agha Hasan Abedi, founder of the Bank of Credit and Commerce International, Saudi money launderer supreme. Here's Bert Lance, President Carter's banker chum who brought poor Jimmy so much grief. Here's young George W, a friend of Bath's, and his dad, then a Nixon loyalist making his way up the greasy pole.
Here's Prince Bandar, Riyadh's long-term fixer and smoother in Washington. George Snr, of course, went on to be Vice-President through the Iran-Contra scandal when the Saudis did him (and Reagan) a monster illicit favour. Fifteen of the 19 9/11 hijackers were Saudis. Osama, of course, was a Saudi hero, valiant for faith. The money that fuelled al-Qaeda, its outrages and its training camps was basically Saudi.
https://www.theguardian.com/theobserver/2004/jul/25/politics