When four American civilian planes brought low the world’s only superpower and greatest nerve center 10 years ago, they made a mockery of the dollar-driven premise that our massive defense establishments can still defend an open society.

Yet instead of re-thinking our defense and foreign policies since then, we’ve become less open and, in a way, weaker — nowhere more so than at the Yale that has honored George W. Bush ’68, John Negroponte ’60, Stanley McChrystal, Tony Blair, and other “practitioners” of grand strategies that have brought us to where we are now.

The question we haven’t answered since 9/11 is whether a society such as ours has the will and moral resources to defend itself. Not as a global directorate, police force or profit center, but as a republic: a wellspring of civic disciplines that sustain a politics of reasonable hope against a politics of fear and misdirected resentment.

But the attacks also mocked claims by the powerless that terrorism is morally or spiritually redemptive. It certainly wasn’t on 9/11. This wasn’t John Brown’s anti-slavery raid on Harper’s Ferry, or guerrilla warfare against Latin American juntas, much less a Velvet Revolution or our own civil rights movement. It was an implosion of anything that anyone who believes in politics can endorse.

The bloody paradox we’ve been ducking shows that our global technologies and investments can’t by themselves dissolve the oldest of errant human impulses — the religious and tribal fanaticism carried by suicide bombers.

It’s too early now to say whether the Arab Spring shows that millions of the aggrieved have learned that hard lesson any better than we’ve learned ours — whether they’ve sidelined terrorism any more than we’ve sidelined the crackpot “realism” of our national-security system and the casino-finance, corporate-welfare, consumer-defrauding tsunami system that drives it.

Places like Yale won’t do better unless we nurture fewer brilliant tsunami surfers and more pearl divers — civic patriots who plumb the undercurrents and unearth the buried treasures of the powerless in our midst. That is 9/11’s hardest lesson. In 2008, Barack Obama seemed to embody and testify to the fact that we’d learned it. But now we’re still discovering how hard that lesson really is.

Jim Sleeper is a lecturer in the Political Science Department.