Saudi Arabia has told the Obama administration and members of Congress that it will sell off hundreds of billions of dollars' worth of American assets held by the kingdom if Congress passes a bill that would allow the Saudi government to be held responsible in American courts for any role in the Sept. 11, 2001, attacks. Adel al-Jubeir, the Saudi foreign minister, delivered the kingdom's message personally last month during a trip to Washington, telling lawmakers that Saudi Arabia would be forced to sell up to $750 billion in treasury securities and other assets in the United States before they could be in danger of being frozen by American courts. The [Obama] administration ... has been lobbying so intently against the bill that some lawmakers and families of Sept. 11 victims are infuriated. In their view, the Obama administration has consistently ... thwarted their efforts to learn what they believe to be the truth about the role some Saudi officials played in the terrorist plot. Families of the Sept. 11 victims have used the courts to try to hold members of the Saudi royal family, Saudi banks and charities liable because of ... Saudi financial support for terrorism. These efforts have largely been stymied, in part because of a 1976 law that gives foreign nations some immunity from lawsuits in American courts. The Senate bill is intended to make clear that the immunity given to foreign nations under the law should not apply in cases where nations are found culpable for terrorist attacks that kill Americans on United States soil.