What is this about? Does anyone here really believe that KSA was behind 9/11? What benefits would such an absurd action exactly give KSA?
9/11 was followed by the catastrophic invasion of Iraq which was totally against the interests of KSA as a state.
http://news.bbc.co.uk/2/hi/middle_east/2773759.stm
OBL who was half Yemeni and half Syrian was stripped off his Saudi Arabian citizenship in 1994.
OBL, Al-Qaeda and Taliban would not even be relevant today had it not been for American involvement in Afghanistan during the Soviet-Afghan war. A conflict where Pakistan, ISI and Zia-ul-Haq were absolutely crucial as a neighboring state. KSA, being in the American camp, was more or less forced to support the US in that endeavor and did so by supporting the Mujahideen financially (which almost every Muslim state with money did, including Western powers other than the US) who were deemed as freedom fighters back then by the entire West because it suited their interests as they fought against their worst enemy - the Soviet Union. Not only that numerous Saudi Arabian individuals, other Arabs and Muslims across the world joined that conflict. A conflict that had nothing to do with KSA and which only had grave consequences for the society in KSA and later gave increased power to the clergy back home. I wish that we (our leadership) had never involved ourselves in that hopeless part of the world. It was a fatal mistake.
Anyway supposed KSA support for 9/11 has already been dismissed in American courts. This is just an attempt to extract money from KSA which will not succeed. USA would have acted long ago against KSA if it was really involved.
Even if we theoretically assume that 1 out of the 15.000 or so House of Saud members were somehow involved in 9/11, that can never be the fault of KSA as a state let alone ordinary Saudi Arabians.
Anyway the same US has committed hundreds of 9/11 since WW2 ended so if anything countries like Vietnam, Iraq, Afghanistan etc. could demand trillions from the US due to their numerous war crimes and illegal actions. Of course that is never going to happen as this is not how the world works like.
Lastly KSA has excellent ties with all world powers, except Russia, although there is even cooperation on this front, all European, Arab and Muslim powers. If the US "abandons" KSA it will be their lose. I am sure that China, who are our biggest trading partner, will want to replace the US as a key ally. Remember what happened in the 1980's vis-á-vis KSA and China? The relationship is much stronger than people believe or can imagine. However I do not believe that it is in the interests of either KSA or USA to cut ties (why should that occur)?
KSA is one of the most powerful, wealthy, biggest and influential states on the planet. This is not the 1950's anymore. Nor is any sane power ever going to invade KSA as that would cause mayhem among the 1.6 billion Muslims. Imagine a foreign power (non-Muslim moreover) occupying Makkah and Madinah. Iraq and Afghanistan (wars that the US did not succeed at if we look at those wars from a full perspective) will look like a picnic trip in comparison. Not to mention the huge size of KSA, geography, climate and the fierce opposition any invader would be met by. ISIS would look like school boys in comparison as well. There is a reason why no foreign power from ancient times to modern times have tried (those who tried failed) to engulf themselves in such a hopeless "project". But we will invite any such fools to try. KSA is no Iraq, Libya, Syria or Afghanistan.