What shall we call the butterfly?

The butterfly I have in mind is the one that illustrates chaos theory: It flutters its diaphanous wings, stirring the slightest breeze, which connects with others until, thousands of miles away, it forms the essential ingredient for a hurricane. Can we call this butterfly Brexit?

I mean, why not? It qualifies. I sat at my desk the day after Britain voted to leave the EU and gazed in horror as, on my computer screen, markets plunged and my modest nest egg became precariously more modest — and all because David Cameron, the posh prime minister, had months before called for a referendum on Britain’s continued membership, having been urged to do so by, among others, Nigel Farage and his rabidly anti-EU U.K. Independence Party.

Who? Nigel who? EU? How had the idiocy of some British politicians most Americans had never heard of resulted in a momentary loss of my not-so-cushy cushion? The market largely recovered within a week, but it might not have and, anyway, when the Dow bounces around by more than 800 points, vast fortunes are being made or lost — not by me or you, maybe, but it’s happening — and it was all because these Brits got to play craps with your investments. They are butterflies.

And so is Gavrilo Princip. He was the Bosnian Serb who, in the summer of 1914, shot and killed the heir to the Austro-Hungarian throne. Within three years, young men from places like Cedar Rapids, Iowa, and Cedarhurst, N.Y., were fighting Germans in France. The Austro-Hungarian Empire is gone, those young men are gone as well, but not the world Princip made. The current mess in the Middle East is partially his doing. Butterflies fly and fly.

And what about Mohamed Bouazizi? The 26-year-old Tunisian fruit vendor set himself afire on Dec. 17, 2010, and pretty soon much of the Middle East was ablaze. This was the beginning of the Arab Spring and it started because a municipal official had confiscated all of Bouazizi’s goods. Her name is Faida Hamdi, and maybe she’s a butterfly too. Either way — Bouazizi or Hamdi — the Arab world was soon in turmoil, Syria had gone to war with itself, the Islamic State came out of nowhere and a measured number of American boots are on the ground once again. Butterflies! But these have the sting of wasps.

The lesson here is modified Teddy Roosevelt: Speak softly and carry a big net. In other words, recognize the interconnectedness of things, of how even the seemingly unrelated can be related. The Syrian civil war is an example. Back when others and I were urging the U.S. to intervene — to stop the slaughter — I did not anticipate that Syria would implode, that hundreds of thousands would die and that millions of refugees would decamp for Europe, swamping Greece and then, as if one step at a time, Western Europe as well. Ultimately, desperate migrants were scrambling into trucks and headed to England.

Much of the reaction in Britain and in the U.S. to the wave of migrants has been to scurry back to the false comfort of isolationism. Quit Europe. Build a wall. This is the message of Donald Trump here or the Brexit people in the U.K. (Also the now-marginally important Bernie Sanders.) Instead of appreciating how things can get out of hand unless the U.S. (and others) intervene, they say that things will get out of hand anyway, that we cannot play world’s policeman — or that sometimes U.S. intervention only makes things worse.

But in Syria, the Obama administration’s inaction loosened a tsunami of migrants that both overwhelmed and terrified Europe. Deep wells of intolerance, as much a part of the culture as knowing the proper wine, bubbled to the surface. Germany is showing the strain. Austria, Hungary and even Poland have veered right, in some cases, troublingly authoritarian. France has a bad case of the nerves and Holland, too, has turned nasty.

I pretty much made back the money I lost the day after the Brexit vote, and anyway my personal P&L — as opposed to the 401(k)s of many others — is hardly the point. Instead, it is that no wall is high enough and no ocean wide enough for us to turn our backs on any part of the world. History shows that inaction is its own kind of butterfly. Perhaps the wings that didn’t flutter in Syria doomed the resplendent goal of a united Europe.

Richard Cohen is a columnist with The Washington Post. His email address is: cohenr@washpost.com.