The Cupar Way peace wall in Belfast, Northern Ireland, is nearly double the height of the Berlin Wall and nearly 50 years old. (Hugh Biggar/The Washington Post)

When I was in college, I took a class on terrorism that covered what are quaintly known in Northern Ireland as the Troubles. Curiously, this helps explain my current feelings about the wall . . . and the government shutdown due to the wall . . . and most other matters wall-related.

Being myself of somewhat distant Northern Irish extraction, I took a particular interest in this section of the terrorism course, especially when the professor livened up a listless discussion by saying, “None of you has asked the obvious question: Why does Britain even want Northern Ireland? What’s there? Guinness?”

For those of us weaned on soft Irish nationalism, this was a bit like being asked, “Why do you want to breathe?” But, as I groped for an answer, I realized it was, in fact, a very good question.

Why were the British so attached to the place? It’s a net drain on their budget, and, frankly, the rest of the British Isles didn’t seem overfond of the Protestant unionists. They had even less affection for the Catholic nationalists, whose radical wing had a nasty habit of setting off bombs in London. And this was decades before the quandary of Northern Ireland’s border with the Republic of Ireland had hopelessly entangled an already muddled Brexit process.

I was hardly alone in my confusion. A lot of people on both sides of the Atlantic were so busy parsing the details of the conflict, and who did what to whom, that they rarely paused to ask the more fundamental question: Why not just let them have what they want when it’s no skin off our nose?

I’m not saying there’s no answer to that question — there is, though it rests on intangibles. I’m simply noting how rarely it occurred to anyone to ask it.

And that, in short, is how I feel about the whole sorry mess that has been convulsing this country for the past few weeks: We spend too much time on “he hit me first!” and too little asking why we care. Why would anyone be willing to shut down the government over something as dumb as the wall?

Clearly, President Trump is doing it because Ann Coulter and her brethren will throw a snit if he doesn’t. But why are they so gung-ho about the wall rather than pushing for an immigration policy that would, I dunno, work? Coulter and company aren’t blinkered enough to actually believe in the wall. Not as an effective anti-immigration measure, anyway — not without the hiring of thousands of new Border Patrol officers. That won’t happen as long as Democrats control the House.

Without frequent patrols, the wall is merely a cumbersome way to spend large sums on construction materials while enraging the ranchers — many of them reliable Republican voters — whose land would have to be seized by eminent domain. But only after years of hearings and appeals. This is the policy equivalent of homeopathic medicine.

But by the same token: Why is this a wall that Democrats want to die on? Their leadership obviously knows it’s a boondoggle. House Speaker Nancy Pelosi (D-Calif.) spent several hilarious moments after Trump’s big speech trying to simultaneously explain that the wall was useless but also deeply inhumane.

So why, then? Because it will cost $5.7 billion? That’s a rounding error in the federal budget. If you made a list of the 10 most extravagantly wasteful and ineffective programs in Washington, the wall wouldn’t even make the list. I doubt it would break the top 100. Yet who’s willing to shut down the government over the much greater sums wasted trying to fix the price of various agricultural commodities? Or buying military aircraft no one wants? Or . . . you get the idea.

There’s an answer to the wall question, and, as in Northern Ireland, it rests on intangibles. Underneath the cries of a crisis at the border, and man’s inhumanity to man, it boils down to this: Team Trump wants to build the wall because Democrats will hate it, and Democrats will hate it because Trump built it. Common sense can’t penetrate this perfect, closed circle of mutual loathing. Which, come to think of it, is a reasonably good description of the Troubles.

We’re hardly on the brink of a shooting war. But the moment you notice any similarities at all between your political system and one that has frequently disintegrated into bitter stalemate punctuated by periodic violence — well, that’s a very good moment to uncircle your wagons and do something else.

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