In an escalation of tensions between nations, Saudi Arabia is threatening to sell off $750 billion in U.S. assets if Congress passes legislation allowing them to be sued for the Sept. 11, 2001 terrorist attacks. The move could destabilize the U.S. dollar.

Some are calling the threat economic blackmail by the Saudis to hide their alleged role of financiers of the worst terrorist attack on U.S soil. Fifteen of the 19 hijackers were Saudi citizens.

The bipartisan Senate bill is co-sponsored by New York Sen. Chuck Schumer, a Democrat, and Texas Sen. John Cornyn, a Republican.

The Obama administration is actively lobbying to derail the bill, arguing the legislation would put overseas Americans at legal risk. According to the New York Times, the Saudi threats have been the subject of intense discussions in recent weeks between lawmakers and officials from the State Department and the Pentagon. The officials have warned senators of diplomatic and economic fallout from the legislation.

The intensity of Obama’s opposition to the bill hits especially hard in New York City, where families who lost loved ones say President Obama is on the wrong side of the issue. The family members are currently appealing a decision made last year that protected Saudi Arabia from a lawsuit charging the country abetted the 9/11 terrorists.

“In their view, the Obama administration has consistently sided with the kingdom and has thwarted their efforts to learn what they believe to be the truth about the role some Saudi officials played in the terrorist plot,” notes the New York Times.

Jim Riches, a retired FDNY deputy chief whose firefighter son Jimmy died in the Trade Center collapse, said: “I’m furious. This is a slap in the face to the 9/11 families. Let them keep their money. We don’t want their money. It’s not worth 3,000 American lives. Call their bluff.”

As America approaches the 15th anniversary of the attacks, Riches expressed fury at Obama. “How in his right conscience can he do this? Meanwhile, they slap us in the face. Stand up for our principles.”

“It’s stunning to think that our government would back the Saudis over its own citizens,” said Mindy Kleinberg, whose husband died in the World Trade Center.

“It’s blackmail, that’s all it is,” said Sharon Premoli, who escaped from the 80th floor of the north tower after the hijacked planes hit. She added flatly, “This has got to stop. The threat shows that they are really nervous. They don’t want to show up in court.”

The financial ultimatum was personally delivered by Saudi foreign minister Adel al-Jubeir during a trip to Washington last month. He told lawmakers Saudi Arabia would be forced to sell hundreds of billions in treasury securities and other U.S. assets before they could be frozen in American courts.

Several economists have expressed skepticism that the Saudis will follow through. They say a sell-off of that size would be difficult to execute, and would end up crippling the kingdom’s economy.

Terry Strada, whose husband Thomas was a Cantor Fitzgerald bond broker on the 104th floor, echoed other family voices by urging the Obama administration to stand its ground against the Saudi financial threat.

“Why do they cave in to the Saudi Arabian government instead of protecting the American people?” she asked. “They’re just trying to keep the Saudis’ dirty little secret. We’ve never held them accountable.”

Strada added, “If the money trail leads back to foreign nations, we have to follow it and take action, and this legislation is a very key part. The only way to combat terrorism is to financially go after people who finance terrorism. Bombs, drones, feet on the ground – you can’t defeat ISIS until you go after their wealthy paymasters.”

The administration, which argues that the legislation would put Americans at legal risk overseas, 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 sided with the kingdom and has thwarted their efforts to learn what they believe to be the truth about the role some Saudi officials played in the terrorist plot.

According to the New York Daily News, under current U.S. law, foreign nations are spared from such lawsuits under the Foreign Sovereign Immunity Act. Any new legislation would need the approval of both houses of Congress and the president. The proposed bill would specifically allow legal action against other countries in cases of an attack on American soil.

In the midst of these tensions, President Obama leaves for a trip to Saudi Arabia on Tuesday. This will be Obama’s fourth trip to Saudi Arabia, more than any other president. The visit will kick off with a bilateral meeting between Obama and the Saudi King Salman.

The Saudi financial threat is renewing a push to declassify 28 pages of an 838-page congressional report about the 9/11 attacks. Currently these critical pages are locked in a secure basement room at the Capitol and remain classified.

It is widely known that two of the hijackers originally landed in Los Angeles, then moved to San Diego where they obtained housing, identification and language lessons. However it is hoped those secretive 28 pages could shed more light on the money, connections and “specific sources of foreign support” behind the hijackers.

In a “60 Minutes” interview, former U.S. Sen. Bob Graham, D-Fla., 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.”

According to NBC News, Graham is the former chairman of the Senate Select Committee on Intelligence and co-chair of the bipartisan joint congressional inquiry into intelligence failures surrounding the attacks. He wants those pages declassified and told “60 Minutes” he believes support for the hijackers came from the government, wealthy people and charities in Saudi Arabia.

The “60 Minutes” report reignited debate and interest in the documents.

NBC reports Jim Kreindler and Sean Carter, lawyers representing the families of victims of the 9/11 attacks, are fighting to have those 28 pages declassified as part of a lawsuit against the government of Saudi Arabia.

Kreindler said the White House could be doing a lot more ensure transparency. “The administration views the 9/11 families suit as an impediment to the U.S.-Saudi relationship,” he told NBC News.

He also points to the position the administration took in 2009, which advocated the Saudi kingdom should be immune from the claims filed by the families of victims because it has sovereign immunity.

Congressman Adam Schiff, currently the ranking Democrat on the Select Committee on Intelligence, does not think releasing the 28 pages would make a difference. He wants them declassified as well, but with an eye toward ending speculation the Saudi government was involved.

“The 9/11 Commission investigated these claims and was never able to find sufficient evidence to support them,” Schiff said in a statement.

Paul Sperry, writing in the New York Post, said, “The Saudi role in the attacks has been ‘soft-pedaled’ to protect America’s delicate alliance with the oil-rich kingdom. That’s quite an understatement. Actually, the kingdom’s involvement was deliberately covered up at the highest levels of our government. And the coverup goes beyond locking up 28 pages of the Saudi report in a vault in the U.S. Capitol basement. Investigations were throttled. Co-conspirators were let off the hook.”

Sperry references his interviews with case agents at the Joint Terrorism Task Forces in Washington and San Diego, the forward operating base for some of the Saudi hijackers, as well as detectives at the Fairfax County (Va.) Police Department who also investigated several 9/11 leads. He says virtually every road led back to the Saudi Embassy in Washington, as well as the Saudi Consulate in Los Angeles.

Yet time and time again, they were called off from pursuing leads on the common excuse of “diplomatic immunity.”

Brian McGlinchey, who runs the website 28pages.org, which describes itself as a hub for the movement to declassify those pages, notes: “Until these 28 pages are freed from the vault, the American people can’t make an informed evaluation of their government’s past and present foreign policy and its execution of the war on terror.”

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