Last week's unanimous passage of a Senate bill making it easier for 9/11 families to sue Saudi Arabia and other foreign terror sponsors was widely heralded as a major victory.

It's more of a cruel hoax.

It turns out that just before the vote, Sen. Charles Schumer and other proponents of the Justice Against Sponsors of Terrorism Act stuffed an amendment into the final draft allowing the attorney general and secretary of state to stop any litigation against the Saudis in its tracks.

Yes, JASTA would remove the statutory restrictions that have prevented 9/11 families from taking the Saudi kingdom to court. But Schumer helped craft an entirely new section to the original bill, giving the Justice and State departments the power to stay court action indefinitely. All they have to do is inform the judge hearing the case that the US government has engaged with ­Riyadh in diplomatic talks to resolve the issue.

The quiet, behind-the-scenes watering-down of the controversial bill explains why it passed without a single Republican or Democratic objection. The White House had lobbied senators heavily to kill the bill.

The section that was slipped in at the last minute — "Stay of Actions Pending State Negotiations" — leaves it up to the secretary of state to merely "certify" that the United States is "engaged in good-faith discussions with the foreign-state defendant concerning the resolution of claims against the foreign state."