This year, there are roughly 31.5 million more Americans than there were on this same date in 2001. Children born that year are entering junior high school, their “memory” of the attacks of Sept. 11, 2001, the vivid video of the two hijacked airliners plowing into the twin towers of the World Trade Center.

The site is now occupied by One World Trade Center at a symbolic 1,776 feet tall, New York’s tallest skyscraper. Three other towers, although not quite so grand, are planned for the site, which is now largely landscaped and adorned with ornamental pools on the footprints of the original buildings. A museum and memorial are nearing completion. The WTC website promises unsurpassed access to public transportation and “world-class shopping.”

Sadly, less well-remembered are the hijacked airliner that slammed into the Pentagon in Arlington, Va., and a fourth, believed to have been headed toward the U.S. Capitol, that passengers forced to crash into a Pennsylvania field near Shanksville. No one aboard any of the airliners survived. The hijackers thought their names would live forever; it’s doubtful that any Americans stopped at random on the street could name even one of them.

But the aftereffects of that day are with us still; in some ways, they are more influential now than in the immediate aftermath.

Take the revelation this year of the breathtaking extent of the U.S. government’s electronic spying on its own citizens. At one time, the loss of privacy and the breach of the implied constitutional right to be secure in one’s communications would have been public outrages. Instead, insofar as the public’s attitude can be characterized, it was, “We didn’t know it for a fact, but we suspected all along that something like this was going on.” And then back to business as usual.

President George W. Bush used the 9/11 attacks and misleading intelligence about weapons of mass destruction — long since destroyed — to leverage us into a war with Iraq that dragged on for eight inconclusive years.

Now, President Barack Obama, with clear evidence of the existence and use of poison-gas weapons in Syria, faces an uphill battle to convince a skeptical Congress to approve even a limited strike to discourage Syria from their use.

In addition to the usual partisanship, Obama is battling post-9/11 cynicism about military ventures. According to Politico, 83 Republicans who voted to support Bush’s invasion of Iraq are still in Congress. Only 10 have come out in support of a strike on Syria; the rest are leaning against or entertaining serious reservations.

Memories of our 9/11 inevitably fade, but we may well have it in our power to prevent someone else’s 9/11, this time caused by nerve gas, not airliners.