But if we continue to place 9/11 at the center of our national consciousness, we will keep making the same mistakes. Our nation’s future depended on far more than the outcome of a vaguely defined “war on terrorism,” and it still does. Al-Qaeda is a dangerous enemy. But our country and the world were never threatened by the caliphate of its mad fantasies…

In the flood of anniversary commentary, notice how often the term “the lost decade” has been invoked. We know now, as we should have known all along, that American strength always depends first on our strength at home — on a vibrant, innovative and sensibly regulated economy, on levelheaded fiscal policies, on the ability of our citizens to find useful work, on the justice of our social arrangements.

This is not “isolationism.” It is a common sense that was pushed aside by the talk of “glory” and “honor,” by utopian schemes to transform the world by abruptly reordering the Middle East — and by our fears. While we worried that we would be destroyed by terrorists, we ignored the larger danger of weakening ourselves by forgetting what made us great.

We have no alternative from now on but to look forward and not back. This does not dishonor the fallen heroes, and Lincoln explained why at Gettysburg.