My memories of 9/11 are very fragmentary, but there is one thing I remember like it was yesterday. I heard the news over the radio at my desk in the TA office (I was a grad student at the time), and I all I could think was "many more people are going to die as a result of this." I knew in my gut right then that the attacks would be the beginning of an awful period.
In the fear and anxiety-ridden aftermath extreme expansions of the surveillance state like the PATRIOT Act and the creation of the Department of Homeland Security sailed through Congress virtually unopposed. America invaded Afghanistan, and then George W. Bush managed to use 9/11 as pretext for a war in Iraq, a nation that had absolutely nothing to do with the attacks. Paranoia struck deep everywhere, and for a time any criticisms of this state of affairs would be met with cries of "treason!" from the jingoistic brigade.
In those dark days I was lucky enough to see a 2004 BBC documentary series, The Power of Nightmares, which no TV outlet in America was willing to show. (A friend got on a free DVD that came with Wholphin magazine.) That series convincingly told a parallel history of neo-conservatism and radical Islamism, and argued that leaders like Blair and Bush needed to pump up the terrorist threat in order to legitimize their own power.
Of course, some things have changed, but the power of nightmares still holds sway. America is out of Iraq, bin Laden is dead, and our current president opposed the invasion of Iraq. However, he has continued the NSA's vast surveillance program, and is more than willing send out unmanned drones to rain death on those he has targeted, and others who just happen to be in the way. Plenty of people are still more than happy to sacrifice freedom when their government assures them it is necessary to ward off the boogeyman. Twelve years after the horrors of 9/11, its nightmare world still dominates our society. It's time for us to finally wake up.