Americans remember the terrorist attacks of Sept. 11, 2001, with sorrow, while our enemies recall them with sickening glee.
And now, shortly before Sunday's 10th anniversary of the attacks, U.S. officials have gotten wind of the possibility that terrorists are planning to "celebrate" the anniversary with new violence.
There are unconfirmed but "credible" warnings that sites in New York City or Washington, D.C., could be hit tomorrow.
Naturally, Homeland Security officials as well as local authorities in those cities are on high alert and are attempting to head off any new carnage. We wish them every success in that endeavor.
But in our vast nation of more than 300 million people, we are reminded again that it is impossible to protect every potential target from deranged attackers.
That makes it important to stay on the offense at home and abroad against those who would like to do our country harm -- to keep them off balance and less capable of launching major attacks.
Meanwhile, U.S. civilians should remain cautious but should not surrender to the panic that would please our sworn enemies.