Saudi Arabia is threatening to sell all it's US assets if Congress passes a bill that potentially could hold it accountable for some of 9/11. Obama is fiercely resisting, but Congress is more united about this than nearly anything about. Also involved are the 28 secret pages of the 9/11 report which apparently hint at involvement by some Saudi officials.
I would be surprised if the American public or Congress is intimidated by this threat. It's true that selling $750 billion of assets would cause some market chaos, but it would also create a fire sale where stocks would be dirt cheap and *(as corrected by WB)* interest rates would go up. It might not get 80 cents on the dollar.
They do have a lot of money, but basically they are a pipsqueak country.