So let me see if I’ve got this straight.

We are at war. We are under a heightened terror alert. Washington being a prime target for attack, security there is especially high. Concrete barricades. Stepped-up patrols. Public buildings closed. The city has been secured to within an inch of its life.

And one farmer on a tractor shuts it down.

OK, maybe that’s not quite accurate. Dwight Watson did not shut Washington down last week when he drove a tractor into a pond near the Lincoln Memorial claiming to have explosives and a willingness to use them. But he sure did paralyze the heck out of the downtown area. Traffic snarled and drivers did, too, as police closed a major thoroughfare and waited him out. The confrontation lasted two days.

It crossed the minds of more than one observer that if the farmer had been a terrorist in possession of, say, a so-called dirty bomb, an untold number of people would have died cursing gridlock while trying to evacuate the city.

For the record, Watson didn’t have any explosives and he surrendered without hurting anyone or being hurt himself. Turns out he’s just a 50-year-old tobacco farmer from North Carolina whose life has taken a rough bounce. Indeed, his hardships sound like a lyric from a country song. He’s deep in debt. Poised to lose the family farm. His mother just went into a nursing home. And his dog is sick.

Ultimately, the poor guy inspires more pity than fear. Still, his misadventure illustrates the oxymoronic tension at the heart of any attempt to secure a free society.

I intend no argument for more concrete barriers. Just an observation that free societies have always been vulnerable to the whims of the individual – the “lone gunman,” if you will. It is part of what freedom means. And that vulnerability didn’t begin on Sept. 11, won’t end with the Iraqi war.

There is a certain sadsack absurdity to Watson’s standoff with police just blocks from the White House. Yet for all that, it offers us an important reminder:

For all the canned foods you hoard, for all the gas masks you stack in your closet, for all the duct tape you have at the ready, you cannot prepare for everything, cannot anticipate every eventuality. And if you could, would you want to? What sort of life would that be?

Your humble correspondent has nothing against preparedness. Heck, at my house, we’ve kept bottled war on hand ever since Hurricane Andrew, almost 11 years ago. Readiness is good. But realism is, too. Perspective is, too.

A few weeks back, I toured the home and burial place of George Washington. And I remember thinking – we think strange thoughts these days – what a great target it would be for some enterprising terrorist. The tomb of the first president, it could be argued, has a certain symbolic resonance. Yet, it’s beneath the radar – not the first place you think of when you think of potential targets. Plus, its only visible defense is an unarmed security guard.

After a few minutes, though, I had to shake that thought loose and get on with the business of sightseeing. Which is to say, on with the business of living.

The only alternative, the only way to ensure that we are always as protected, safe, secure as possible, is to live under lockdown. Which is no alternative at all.

The truth is, simply leaving the house is an act of faith. But then, it always was.

That’s something we sometimes forget in the midst of all the terror warnings and the talking heads on television demonstrating the proper use of duct tape. Then one sick-of-it-all farmer rolls a tractor up to a national monument in the middle of arguably the most secure city on Earth.

I don’t know about you, but I had to shake my head and smile. Not at Watson’s woes, but at this fresh demonstration of the old axiom: If it ain’t one thing, it’s bound to be another.

That’s freedom. Indeed, that’s life.

Leonard Pitts Jr. is a columnist for the Miami Herald. His e-mail address is: [email protected].