After the terrorist attacks of Sept. 11, 2001, the phrase “the new normal” entered the national vocabulary. Today, as America marks the 10th anniversary of those attacks, the definition of “normal” we coined a decade ago isn’t quite as new anymore.

The “new normal” that once shocked us — heightened security screenings, threat warnings, the routine of a nation constantly at war — now seems utterly conventional. Most of us have learned to accept what once seemed unacceptable.

We know that the world changed a decade ago today, and we know that America had to change with it. But there is a danger, too, in accepting the new realities of this new age as irreversible, inevitable.

We must not forget that for nearly a decade, men and women in America’s armed forces have been fighting abroad, separated from their families. Some have suffered injuries from which there’s no hope of full recovery. Others have died in battle.

The “new normal” should not be an occasion to take these sacrifices for granted. We must not become a nation for which war is ever considered casual.

Today, we remember those who died in the attacks on Sept. 11, 2001, and those who have since died in the war on terrorism. Today, we also hope and pray for a better “normal” for America and the world — one in which war is no longer necessary, and terrorism is a thing of the past.