What might cause another 9/11?

(updated below [Wed.] – Update II [Wed.])

Today’s defense of President Obama from Andrew Sullivan is devoted to refuting Conor Friedersdorf’s criticism of Obama’s drone program. Says Sullivan:

What frustrates me about Conor’s position – and Greenwald’s as well – is that it kind of assumes 9/11 didn’t happen or couldn’t happen again, and dismisses far too glibly the president’s actual responsibility as commander-in-chief to counter these acts of mass terror.

This is exactly backward. I absolutely believe that another 9/11 is possible. And the reason I believe it’s so possible is that people like Andrew Sullivan — and George Packer — have spent the last decade publicly cheering for American violence brought to the Muslim world, and they continue to do so (now more than ever under Obama). Far from believing that another 9/11 can’t happen, I’m amazed that it hasn’t already, and am quite confident that at some point it will. How could any rational person expect their government to spend a full decade (and counting) invading, droning, cluster-bombing, occupying, detaining without charges, and indiscriminately shooting huge numbers of innocent children, women and men in multiple countries and not have its victims and their compatriots be increasingly eager to return the violence?

Just consider what one single, isolated attack on American soil more than a decade ago did to Sullivan, Packer and company: the desire for violence which that one attack 11 years ago unleashed is seemingly boundless by time or intensity. Given the ongoing American quest for violence from that one-day attack, just imagine the impact which continuous attacks over the course of a full decade must have on those whom we’ve been invading, droning, cluster-bombing, occupying, detaining without charges, and indiscriminately shooting.