Nine years ago today terrorists hijacked four airplanes, flew two into the World Trade Center towers in New York City and another into the Pentagon in Virginia. The fourth airplane crashed in Pennsylvania after passengers on board struggled with the hijackers.

Sept. 11, 2001, is the day America lost its innocence. In much the same way that New Orleans-area residents divide history into pre-Katrina and post-Katrina periods, for U.S. citizens pre-9/11 America was, in many ways, a very different place.

Since then, the world has seemed a little darker, the enemies a little closer.

And war has become a constant. While it is no longer front page news, its effects hang over the nation like a specter, the faint buzzing of a mosquito in our collective ears.

Gov. Bobby Jindal recently ordered all state buildings to fly their flags at half staff in remembrance of all those who have given their lives over the past nine years defending this country’s safety, security and ideals.

At the same time a tide of intolerance is rising in the U.S. as protesters attack the rights of citizens to build a mosque near ground zero in New York and a Florida pastor threatens to burn copies of the Quran, the Muslim holy book.

The right to protest is one of those issues for which the soldiers abroad are fighting.

But so is the freedom to practice whichever religion one so chooses.

So today if you are out and see the Stars and Stripes flying a bit lower than usual, stop and take a minute to think about the soldiers fighting to preserve our freedoms. Also think about what those freedoms are, and remember that to deny those freedoms to any citizen of the United States is to deny them to all.