Today marks the 11th anniversary of the Sept. 11th terrorist attacks. What, if anything, have we learned? In a Saturday statement, President Obama struck an upbeat note: "The legacy of 9/11," he said, is "the ability to say with confidence that no adversary and no act of terrorism can change who we are."

Who's he kidding? For us ordinary schlubs who don't own our own planes, a trip to the airport provides less reason for optimism. We shuffle shoeless through the security line, at the end of which government agents will either grope us or look at us naked. And despite his campaign trail promises to "set an example for the world that the law is not subject to the whims of stubborn rulers," Obama has forged an expanded "Terror Presidency," with dangerous new powers for all future presidents to wield.

Sept. 11th has changed America radically—and not for the better.

As security analysts John Mueller (a Cato senior fellow) and Mark G. Stewart point out in an important new article in International Security, it's far from clear that any of this was necessary. Though the FBI initially insisted America was riddled with up to 5,000 trained Al Qaeda operatives, an internal agency memorandum, leaked in 2005, admitted that "To date, we have not identified any true 'sleeper' agents in the US." At a certain point, Mueller and Stewart suggest, the absence of evidence becomes evidence of absence.

Last Thanksgiving, the Department of Homeland Security earned a lot of Twitter snark for its video warning Americans of the dangers of deep-frying turkeys. But turkey fryers kill about five Americans a year; jihadists have killed about 16 here since 9/11.

"In the eleven years since the September 11 attacks, no terrorist has been able to detonate even a primitive bomb in the United States," Mueller and Stewart note.

If you're having trouble with pipe bombs, Weapons of Mass Destruction are almost certainly beyond your competence. Though, as the authors explain, erstwhile "enemy combatant" Jose Padilla once planned a domestic nuclear attack: "His idea about isotope separation was to put uranium into a pail and then to make himself into a human centrifuge by swinging the pail around in great arcs."

Mueller and Stewart quote anthropologist Scott Atran: "Perhaps never in the history of human conflict have so few people with so few actual means and capabilities frightened so many." And we have erected monuments to that fear—vast bureaucratic pyramids erected in Al Qaeda's honor.

In their 2011 book, "Top Secret America: The Rise of the New American Security State," Washington Post reporters Dana Priest and William M. Arkin chronicle the growth of the post-9/11 "Intelligence-Industrial Complex": 1,200 agencies occupying three Pentagons' worth of office space. We've spent "hundreds of billions of dollars to turn the machine of government over to defeating terrorism," without seriously examining what we're buying with our money and lost liberty.

Meanwhile, 2008's promises to bring our National Surveillance State under the rule of law have vanished from the 2012 Democratic platform. In the middle of a fiscal crisis, Congress and President Obama have been subsidizing dystopia—using Homeland Security grants to fund the proliferation of surveillance cameras, drones and military ordnance for small-town police departments.

To commemorate the 10th anniversary of 9/11 last year, the conservative Heritage Foundation settled on a theme: "Never Quit." In the accompanying video, Heritage warned that "our continued security is anything but certain … withholding crucial resources and needlessly slashing defense" would dishonor those who died in the attacks. "We must never forget, and we must never quit."

Say what you will about Barack Obama–he's no quitter.