"This is a perfect play into our hands," said Ron Motley, the colorful tort lawyer who is heading up an army of litigators who are representing the families of 9-11 victims. "We smoked out the prince."

By claiming his conduct was official policy and then introducing affidavits from officials of the charities to back it up, Motley said, the defense lawyers have opened up their client and his supporting witnesses to "discovery"--pretrial proceedings in which plaintiff's counsel can grill them about their claims and the extent of their knowledge of how the royal funds were spent. Motley said the filing may eventually open up the kingdom itself to be named as a defendant in the case.

Whether or not that ever transpires will depend on U.S. Judge James Robertson, who is overseeing the sprawling lawsuit and who so far hasn't tipped his hand. But the recent flurry of legal maneuvering only underscores the enormous stakes in the proceedings.

Lawyers for the defendants have derided the entire 9-11 case as a fanciful concoction of conspiracy theories and speculative musings that bear little, if any, relationship to the actual events of 9-11. They also say that much of the complaint involves matters that do not belong in a U.S. courtroom, such as the claim that members of the Saudi royal family are anti-American, seek to export "Wahhabi ideology"--the country's puritanical brand of Islam--and that Prince Sultan has "publicly accused the 'Zionist and Jewish lobby' of orchestrating a media blitz against the Saudi Kingdom."

"Surely," the lawyers for Sultan write in their brief, "the plaintiffs do not contend that an American court can or should pass judgment on the religious beliefs or practices of Saudi Arabia or determine whether its government is "anti-American."

But however persuasive (or not) those arguments are, there may be a host of other factors that influence how the case plays out. Despite initial feelers by lawyers for the Saudis, few now expect the State Department to intervene with Judge Robertson to ask that the case be dismissed. (It's a political nonstarter, lawyers on both sides say.) In the meantime, although President Bush and his senior aides have publicly praised the Saudis for their "cooperation" in the war on terror, officials at the Treasury and Justice departments have privately expressed deep frustration over the failure of the Saudi government to impose stricter controls over their Islamic charities and turn over crucial evidence about the murky flow of money to Al Qaeda.