I came across an episode of the TV series Vikings that stuck with me long after watching it, and the lesson it carries feels as relevant today as it did a thousand years ago.

An early medieval English king decides he is done with the Norse people in his country, and his solution is to eliminate them entirely. He launches a campaign to kill all of them, including men who had settled peacefully, served loyally, fought alongside his own forces, and integrated so completely into English culture that they had nearly forgotten their own language and customs. When one of his own guards pointed to how long they had lived there and how much they had contributed to the kingdom, the king’s response was chilling. You may look like us and live like us, but you are not us, and you never will be. He moves forward with the plan and kills them all, including that same guard.

What follows is entirely predictable in hindsight. The Viking response is swift and severe. What had been a manageable tension becomes a full-scale invasion. Canute assembles one of the largest Viking armies ever seen, both Christian and Pagan fighters united, all driven by the same desire for vengeance against the king who ordered the slaughter.

Within no time at all, a Norse king is sitting on the English throne. The ruler who committed the original atrocity does not live to see how completely it unravels, but his son does. His son inherits the wreckage of that decision and loses both the kingdom and his life because of it.

It is one of those storylines where you can draw a straight line from a single choice to a catastrophic outcome, and it lands because the underlying history actually backs it up. Fear and suspicion closed off every path that might have led to actual stability. The deep irony is that by trying to eliminate a perceived threat through force and exclusion, the king manufactured the exact disaster he was trying to prevent.

Sometimes the fastest road to catastrophe is believing a complicated problem has a simple, final answer. Vikings illustrates that truth better than most shows ever attempt to.