Viewed from 2018, the world of pre-9/11 America looks like a model of peace and sanity.

It wasn’t, of course, but compared to what we’ve had since then, it seems that way.

As of now, America’s crisis du jour is a caravan of migrants trying to crash our southern border.

If I were in their situation, I’d probably try the same thing. Let’s see: Should I move from a poor, crime-ridden country to one that is still relatively prosperous and relatively lawful, that has generous welfare benefits and armies of lawyers ready to fight on my behalf? Who wouldn’t want to do that? Hundreds of millions of people would.

Of course, the migrants themselves are in a sense only the hammer. The nail — or perhaps “vase” is a more apt metaphor — is the American border. The hands wielding the hammer belong to people who have all kinds of motivations. Some are noble. Some are hateful. Some are merely self-serving.

But none of it was hard to see coming. Back in the relative peace and sanity of pre-9/11 2001, I wrote my dissertation in economics. From the introduction:

“These economic developments dovetailed with a growing consensus among Western political elites: the idea that separate nation-states were the main cause of the carnage and terror that blighted what should have been the most glorious period in human history — and the conviction that some form of globalized political order was the only solution.

The 20th century saw diseases wiped out, famine beaten back if not defeated, and poverty — real poverty, not just the relative poverty of any society’s least fortunate — made into a distant memory held only by the very old, at least in free-trading Western countries.

And yet this same century saw destruction and death on a scale beyond Dante’s worst nightmares of the Inferno. Bloodied by the seemingly endless conflicts of the 20th century, Western elites began to look to international arrangements for relief: from the League of Nations and the United Nations to the European Union, NAFTA, and the World Trade Organization.

Supported by private groups such as United World Federalists for idealistic reasons, and by the Soviet Union’s Comintern (Communist International) network for reasons less idealistic, the movement toward eliminating separate nation-states gathered steam from the First World War to the turn of the 21st century.

This movement and evolution provided a legal and political framework in which globalization could become the dominant trend in hitherto more localized economies. Economists were on hand to cheer it along for the prosperity they felt certain it would bring. But what kind of prosperity it would be — and for whom — were questions unaddressed in mainstream discussions of the subject.”

We’re still having the debate. Should nation-states continue to exist? What kind of prosperity, and for whom? Do people have a right to their own country, culture, and history — and the right to keep other people out? Or does everyone else in the world have a “right of return” to lands that they claim as their own?

Our attitudes about border-crashers depend largely on how we answer those questions.

Check out my new book Why Sane People Believe Crazy Things: How Belief Can Help or Hurt Social Peace.