It was an unexpected bonus. Our leisurely vacation trip included a stop at a faraway ancient city, one that triggered surprising perspective on a current day issue.

This past Sunday, as part of a Viking Mediterranean cruise, my wife and I spent the morning in the ancient port city of Ephesus, on the west coast of Turkey. If the name Ephesus doesn’t ring a bell for you, it’s probably because nobody lives there anymore.

One hundred years before the birth of Jesus Christ, Ephesus was already about nine centuries old. By then it was a bustling city of about 250,000 residents — second-largest in the world — the most important trading city on the Mediterranean Sea, and the economic capital of the Roman Empire. It was a prosperous, highly cultured, and technologically advanced corner of the world, replete with lavish homes for the wealthy, magnificent buildings, marble-paved roads, and a 15,000-seat outdoor arena.

It was a remarkably resilient city. Over its 1,600-year lifetime, Ephesus survived earthquakes, foreign invaders, epidemics, and domestic upheaval. But in the 6th century AD, a massive earthquake triggered economic collapse so profound that it literally erased Ephesus from the map. Were it not for nearly a century of archeological reconstruction, there would be little physical evidence that Ephesus had ever existed.

Wandering through its painstakingly reassembled ruins (now a UNESCO site), one cannot help but wonder how that once-magnificent city came to such an abrupt end. Why did it fail while others in the region still thrive today? And what does the sudden demise of 1,600-year-old Ephesus say about the future prospects of our fledgling USA?

We Americans have come to enjoy a comfortable (and probably unwarranted) sense of permanence, as if a successful future is all but assured. We tend to look at the colossal misfortunes that struck ancient places like Ephesus as historical aberrations, irrelevant to modern times.

But why so? In many respects, ancient Ephesus and today’s USA — both prosperous, sophisticated, and seemingly in charge of their destiny — are remarkably similar. That’s hardly a basis for substantive assessment of our nation’s future, but it’s worth a thought.

Most of the calamitous failures of ancient civilizations were triggered by either violent acts of nature (earthquakes, floods, volcanos) or by marauding powerful invaders. Hopefully, 17 centuries of advancement since the demise of Ephesus have taught us a thing or two, but we shouldn’t declare immunity quite yet. Consider:

1.) We live on an unforgiving, uncontrollable planet. This earth has been spinning through space for a long time. We temporary inhabitants may pretend we’re in command, but we actually have little control over it.

The earthquake that brought Ephesus to its knees in the 6th century AD was comparable to the series of earthquakes that killed over 40,000 in Eastern Turkey just a few weeks ago. The earth is just as capable of behaving destructively as it was centuries ago; what has changed is mankind’s improved ability to anticipate and adapt to such events. And the recent death toll in Turkey tells us that we must do better.

These days, we are obsessed with the “existential crisis” of climate change. Many argue for enormous expenditures and disruptive changes to the energy production needed to support the health, safety, standard of living, and life expectancy of the earth’s eight billion residents — all in the misguided hope that we can alter the cyclic climactic changes that have occurred for eons.

As with calamitous natural disasters like floods and tornadoes, it would be far more productive to adapt to climate change than to try to prevent it.

2.) As far as marauding invaders go, look no further than the Russian assault on Ukraine or China’s designs on Taiwan. Just like a millennium ago, the single most effective way to protect our nation is to maintain a superior defensive capability and to make it clear to prospective adversaries that we will use it if need be. And while we’re at it, let’s not forget to close our borders.

3.) Any nation’s ability to ride through major crises demands a healthy, sustainable economy. The earthquake that struck Ephesus 1,500 years ago destroyed the seaport that was its economic lifeblood. That was a death blow — the city’s relatively one-dimensional economy, totally dependent on trade, could not survive the loss of its seaport.

Of course, the U.S. economy is far more robust and diverse. But inflation is unacceptably high, and our current rate of spending (and borrowing) is unsustainable. Some Democrats insist that Congress abolish the debt ceiling with no associated spending limits, essentially asking for a credit card with no cap. That’s a recipe for unprecedented economic disaster.

What happened in Ephesus is ancient history. But the old axiom — we’re doomed to repeat the history we don’t remember — has no statute of limitations.