The other thing we must not do is to demonize a whole people, a religion.
Picking on Muslim people is cheap. That's fear and ignorance talking. It's too easy. And going to war with the so-called Muslim world won't accomplish our goals.
If those who are responsible happen to be Muslims, they will be punished not because of their religious beliefs but because of what they've done. And they will be punished, if death and punishment are the same thing.
President George Bush spelled that out in his address to the nation on Tuesday night.
"The search is under way for those behind these evil acts," the president said. "I've directed the full resources of our intelligence and law enforcement communities to find those responsible and bring them to justice.
"We will make no distinction between the terrorists who committed these acts and those who harbored them," he said.
This last sentence is the key to his speech. It was simple, and the world understood it.
There were those who wanted more emotion from Bush, those who are interested in style, and those who wanted more presidential hand-holding, some gushing, perhaps some tears or biting of the lower lip.
But that's show biz. It's not necessary.
What is necessary is that sentence, the part about there being no distinction between terrorist and host nation.
It lets the world know what will happen, that this empire, and we are an empire, won't allow such coziness anymore.
If it happens in Afghanistan, if America aims at the people and the land there, the world will understand that there is a price to be paid and those who allow terrorists to operate in their country will pay it.
There is an obligation between the dead and those of us still living, a blood obligation.
It is our obligation to demand it.