A grass-roots doctrine of preemption

President Bush has never backed away from his doctrine of preemption to justify ousting Saddam Hussein from power in Iraq - and the idea of "hitting them before they hit us" has become a cornerstone of the global fight against Al Qaeda.

As the war on terror continues, I'll be curious to see how the notion of preemptive action percolates into other aspects of American culture.

If there is decisive and compelling evidence that something terrible is about to happen, taking steps to head off the problem before it occurs seems perfectly reasonable. And in the realm of international relations, a high danger level is the standard argument for using preemptive military action.

So, does this philosophy have implications for our everyday lives? I pondered that recently while standing next to an irate customer in a bank lobby.

The guy was wearing scruffy clothes and a baseball cap. He looked as if he might be on a lunch break from a construction job, and he'd been waiting in the "merchant only" line as I took my place in the regular line, so we were literally side by side.

The merchant teller may have told him to stand back because she had a customer at her window. Whatever she said made him angry.

The guy began to berate the teller loudly. He objected to her tone of voice, and said it was condescending. She said, "Do you want me to call security?"

I glanced up at the video monitor above the tellers and there I was, right next to the guy, looking befuddled and nervous. I imagined how the scene would play as a segment on the nightly news, and the announcer's voice saying, "Watch closely now, as the suspect suddenly grabs the customer next to him and [fill in violent ending here]."

Was this a moment for preemptive action on my part?

The man seemed determined to have an argument. The teller pointed him toward the branch manager, who was sitting at a nearby desk with another customer.

I was hoping the manager would get up and exert a calming influence, but he remained seated and said, "You need to settle down and I'll talk with you when I'm finished with this customer!"

I kept looking at the video monitor, the angry man gesturing toward the manager and me standing like a lump.

And I asked myself: Should the government or the police be tracking people like this irate customer? Do Americans have a right to behave this way when we're in a war on terror? Is he a potential threat, someone who may go home and begin building an improvised explosive device?

The argument was tapering off when I left. I don't think the guy was dangerous. But can I be sure?

I wonder what President Bush would do.

• Jeffrey Shaffer writes about media, American culture, and personal history.