I have not seen the video.

Not saying I won't, but for now, I've chosen not to. To rush online and seek out cellphone footage of two fanatics with machetes who butchered a British soldier in London on Wednesday, to watch them standing there, hands painted red with his blood, speaking for the cameras, would feel like an act of complicity, like giving them what they want, like being a puppet yanked by its strings.

Sometimes, especially in the heat of visceral revulsion, we forget an essential truth about terrorism: The people who do these things are the opposite of powerful. Terror is a tactic chosen by the impotent.

These people have no inherent power. What they have is a willingness to kill randomly, ruthlessly and indiscriminately.

But they represent no existential danger. The United States once tore itself in half and survived the wound. Could it really be destroyed by men using airliners as guided missiles? Britain was once bombed senseless for eight months straight and lived to tell the tale. Could it really be broken by two maniacs with machetes? Of course not.

Terrorism's threat lies not in its power, but in its effect, its ability to make us appalled, frightened, irrational, and, most of all, convinced that we are next, and nowhere is safe. I'm thinking of the lady who told me, after 9/11, that she would never enter a skyscraper again. As if every tall building in America was suddenly suspect. And I'm thinking of my late Aunt Ruth who, at the height of the anthrax scare, required my uncle to open the mail on the front lawn.

I am also thinking of the country itself, which, in response to the 9/11 attacks, launched two wars - one more than necessary - at a ruinous cost in lives, treasure and credibility that will haunt us for years.

Have you ever seen a martial artist leverage a bigger opponent's size against him? That's the moral of 9/11. The last 12 years have shown us how easily we ourselves can become the weapon terrorists use against us. This is especially true when video footage exists. After all, getting the word out, spreading fear like a contagion, is the whole point of the exercise.

That could not have been plainer last week. Having reportedly run the soldier, Lee Rigby, down with a car, having hacked him to pieces with machetes, these men did not blow themselves up and they did not run. No, they spoke their manifestoes, their claims of Muslim grievance, into the cell phone cameras of passers-by.

Almost instantly, this was all over television and the Internet. The voices of impotent men were magnified to a global roar. Almost instantly, we all stood witness.

Terrorism uses its minimal power to achieve maximum effect and this is easier than ever on a planet that is now so networked and webbed. Our connectivity is exploitable.

But in the end, no, these people cannot destroy us. Can they grieve us? Certainly. But they cannot destroy us unless we help them do it.

Their most lasting violence is not physical, but psychological - the imposition of fear, the loss of security. We cannot control what such people do. But we can control our reaction thereto. So let it be finally understood: From time to time, we will face the desperate evil of impotent men. But the only power they have is the power we give them.

I propose we give them none.

Email Leonard Pitts Jr. at lpitts@miamiherald.com.