My last post got me thinking about borders, which, along with inflation, was a main driver in last month’s election.

But what exactly is a border?

According to National Geographic, “A border is a real or artificial line that separates geographic areas. Borders are political boundaries [that] separate countries, states, provinces, counties, cities, and towns. A border outlines the area that a particular governing body controls.” However, “borders change over time” through conquest, peaceful sale or trade, or international agreements.

Ever since the first humans climbed down from trees for good, we have been wanderers. We have also been settlers. And we have carried those conflicting needs with us as we walked from southern Africa to Patagonia. Hewing mostly to a coastal route – which Spencer Wells described as “a sort of a prehistoric superhighway” – this remarkable journey took between 60,000 and 115,000 years, which I realize is not a particularly precise number; but it’s a very long way.

As we came to inhabit every part of this earth, all the other species learned a painful lesson: there is no stopping us. What the March 2006 issue of National Geographic proclaimed, “the greatest journey ever told” is also the story of how hard we have been on the earth and our cohabitants.

While our wandering ancestors set boundaries for settlement and protection, the concept of fixed borders drawn on a map developed much later – probably with the rise of nation-states in Europe 300-500 years ago. These borders were meant to impose order, both externally, by protecting the state from invasion, and internally, by creating a sense of shared nationality among those inside. Today, as national borders have become increasingly porous, they are ever more stridently defended. A nation, we are told, requires strong borders.

It might be time to rethink that.

First of all, although modern borders often conform to a geographic or physical feature, such as a river or sea, they are, in the end, lines on a map drawn by humans, often in the aftermath of war.

Therefore, they are not permanent, even though they may last a long time. Consider some of the history’s monumental efforts to maintain them:

• After WWI, the French built the Maginot Line to impede a future German invasion. Unfortunately, the Germans not gone around I, and six weeks later, they marched into Paris.

• What’s left of the Great Wall of China is now a tourist attraction.

• The Berlin Wall lasted barely 30 years.

• Then there’s the border between North and South Korea. Known as the Demilitarized Zone, it is, in fact, “the most heavily militarized border in the world.”

The purpose of the Korean border is not just to keep some people out; it is to keep other people in. How often have we seen that in history? – in Europe’s ghettos, in South Africa’s townships, in our Jim Crow south, where the walls were often figurative but no less real. Such borders are brutal, but they are not permanent.

In today’s world, borders seem everywhere under siege. Imperialists like Putin and Xi blow through them. Neither Hamas not Netanyahu show them much respect. For multi-national corporations and industrial agriculture, borders are at best an inconvenience. Facebook’s algorithms don’t know what they are.

For many Americans, our border with Mexico is sacrosanct. Not so much with Mexico’s border, even though, of course, it’s the same border.

As human history has demonstrated over and over again, you may slow, but you will not stop, the movement of people who are desperate.

Therefore, you cannot solve problems at the border without addressing their underlying causes . . . on both sides of the line – for a border, by definition, is a shared endeavor. As President Claudia Sheinbaum wrote to President-elect Donald Trump, you aren’t the only one with a border problem; we’ve got one, too.

The time has come to rethink the whole concept of borders in our interdependent and interconnected world, whose endless diversity should be calling us out instead of walling us in.