The Mafia, in its heyday, ran lucrative protection rackets. Pay them and your business would be kept safe from "unforeseen" threats. Don't pay them and your business might go up in smoke with you inside.

Today, things are more sophisticated.

The New York Times reports that Saudi Arabia, playing the role of Mafia extortionist, has threatened to "...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."

The Saudis are estimated to hold about $750 billion in treasury securities and other assets in the U.S. and the concern is that they might sell them before American courts could impose a freeze. The Obama administration opposes the bill, saying it could potentially open the kingdom to lawsuits from relatives of the dead and injured. So?

Why do the Saudis oppose this bill, which enjoys bipartisan support? Could it be because, as many believe, they helped facilitate the greatest mass murder in American history? Fifteen of the 19 men involved in the terrorist plot were Saudi citizens and that country promotes the most extreme form of Islam known as Wahhabism.

Adding to the suspicion that there is more to be learned about Saudi Arabia's role are 28 pages contained in the 9-11 Commission's report censored by the Bush administration for "national security reasons." Need more? According to government documents obtained by Judicial Watch, "160 subjects of the Kingdom of Saudi Arabia, including but not limited to members of the House of Saud and/or members of the bin Laden family fled the U.S. (on chartered planes when all other aircraft were grounded) between September 11, 2001 and September 15, 2001."

In an April 10 appearance on the CBS program "60 Minutes," former Florida Democratic Sen. Bob Graham, who chaired the Senate Select Committee on Intelligence at the time the report was being written, said: "I think it is implausible to believe that 19 people, most of whom didn't speak English, most of whom had never been in the United States before, many of whom didn't have a high school education, could've carried out such a complicated task without some support from within the United States."

Graham thinks the hijackers received active support and guidance from rich Saudis, Saudi charities and top members of the Saudi government.

This is a matter that is easily resolved by releasing the 28 pages. The relatives of the dead have a right to know who funded the terrorist attack that killed their loved ones. Justice demands it and if compensation is awarded, the Saudis, who have made billions from oil sales to the West, can afford it.

The intent of the Senate bill is to clarify the immunity normally given to foreign governments. It says such immunity should not apply when nations are found culpable of committing terrorist attacks that kill Americans on U.S. soil.

The Obama administration claims that weakening the immunity law could put U.S. corporations, the American government and its citizens at legal risk because other nations might retaliate with similar legislation. The difference is that U.S. citizens are not hijacking planes and committing mass murder in other countries. The bill's sponsors, notes The New York Times, "have said that the legislation is purposely drawn very narrowly -- involving only attacks on American soil -- to reduce the prospect that other nations might try to fight back."

For too long Republican and Democratic administrations have ignored the actions and teachings of Saudi Arabia, including textbooks used in Islamic schools that denigrate Jews and other "infidels" and the building of mosques that some imams are using to spread hate and recruit suicide bombers.

This bipartisan bill should pass, and if the president vetoes it, he should explain his reason to the families of the dead.

Cal Thomas is America's most widely syndicated op-ed columnist. He joined Fox News Channel in 1997 as a political contributor. His latest book is "What Works: Common Sense Solutions for a Stronger America" is available in bookstores now. Readers may email Cal Thomas at tcaeditors@tribune.com.