Liz and I were watching the news. The story was about preemptive reduction of cruising in the streets of Milwaukee--stopping it before anything bad actually happens. A police officer intoned seriously into the off-screen microphone, "The problem with cruising is that it leads to stopping."

We looked at each other and burst out laughing. That's sort of like saying, "The problem with life is that it leads to death." It's true, I guess, but what can you do with a comment like that?

 Speaking of death, an Associated Press story being widely disseminated is Soldier son of Dutch defense chief killed (Milwaukee Journal Sentinel headline). Lieutenant Dennis van Uhm was the victim of a roadside bomb in Afghanistan. Dutch prime minister Jan Peter Balkenende characterized this loss as "an unprecedented tragedy."

Well, no. It's a very "precedented" tragedy. Van Uhm is the 16th soldier from the Netherlands to die there. Nearly 500 American soldiers have died in Afghanistan, and the death toll for soldiers from the West there is nearly 800--and continuing to rise. In Iraq, 4,000 US soldier deaths have preceded the next one. And the one after that. In war, tragedy is the coin of the realm.

Since my mother's death a couple weeks ago, I've had a harder time than usual listening to pious rhetoric and words that sound like they mean more than they do. Maybe if I'd lost a soldier son, I'd feel differently about the inflated language used to turn a personal loss into a political lever. I'm glad not to know the truth that would come from that experience.

President George W. Bush believes that the safety of the United States depends on "preventing (Iran) from having the knowledge necessary to make a nuclear weapon."

It's an extraordinary idea, this "knowlege prevention." Google doesn't even recognize the term. Anything you find with both "knowledge" and "prevention" is about avoiding losing knowledge.

The first time I heard the expression "preventing . . .knowledge" in October, I wrote it off as more language blundering. But with the new National Intelligence Estimates-fueled debate about whether Iran really has stopped pursuing nuclear weapons, the phrase is being used with the frequency of propaganda.

I'm not sure how you enforce ignorance. Shut down the schools? Burn the books? Imprison the scientists? The knowledge in question doesn't belong to the United States. It belongs to those who can discover and apply it.

This isn't to say that Iran isn't dangerous. It certainly is. Whatever National Intelligence Estimates show, it seems reasonable to assume that if Iran isn't pursuing nuclear weapons at the moment, it will. Knowledge, after all, is power--nuclear or otherwise.

The work of someone who calls himself the leader of the free world isn't to prevent people from having knowledge. It's to persuade them not to use it badly--the work of diplomacy.

Sometimes, force is needed to prevent bad acts. But not to prevent knowledge.