About a year ago I really put my foot in my mouth. Our Ukrainian housekeeper was over when a Russian friend stopped by.

“Hey, you guys should meet,” I said with a weird sense of excitement and naïveté. “You’re both from a similar place — Russia and Ukraine!”

The look on their faces immediately educated me. They could barely look at each other. When their eyes met for a brief moment, the glance was steely and awkward.

I’ve been thinking about that moment a lot lately. It revealed something dark and ominous. There was deep-seated distrust and disdain between two strangers that I didn’t fully understand.

A few weeks ago I saw my Russian friend and asked what he thought of the impending invasion.

“Screw Ukraine,” he said, almost nonchalantly. “Who gives a damn about them?”

Meanwhile, our Ukrainian housekeeper’s heart is broken. Her family is there, including her husband, whom she fears she might not see for some time. To her, that’s the reality of Putin’s dangerous actions.

A large-scale invasion by a major military power is not something most Americans have ever seen. For many, images of tanks and troops rolling into a European country are the stuff of grainy black and white film newsreels.

But all that could change at any moment. If and when one man says “go,” we will see a real modern day war. Ukraine — 233,000 square miles home to 44 million people — will see its cities and countryside overrun with tanks, troops, air power and artillery shells.

Their world will never be the same — but neither will ours.

Americans will still watch our TV shows and sporting events. March Madness is right around the corner, so are the Oscars. But we’ll also see — if we care to — news clips and cell phone videos of the horror of war that will be playing out across the globe. We’ll see panic, evacuations, destruction, death. We’ll be reminded of the cruelty and senselessness of war and the power one person with unchecked power can yield.

It’s not difficult to imagine what Russia — its 200,000 troops already poised around Ukraine — can do to a much weaker neighbor. What’s harder to imagine is the ripple effect that might soon be unleashed throughout the world.

Historians teach that major historical events are usually the consequence of previous events, even if seemingly disconnected. Yale professor David Blight writes about how modern day America is the direct result of the Civil War. He traces practically every prevailing social and political dynamic — race relations, cultural divides, intolerance, populism — over 150 years. Look closely, he says, and you’ll see how most every chapter in history is connected to a previous chapter.

Putin seems to want to right a past wrong that was done to the Soviet Union. If he proceeds, the whole world will be watching — particularly other autocrats who just may be encouraged by what they see. What might this mean for other vulnerable places in the world, with neighbors who have threatened to invade and surely wondered how the world would react if they launched a full-scale war?

We could soon be watching Russian tanks in Kiev. But also keep an eye on other places like Taiwan or Seoul or Jerusalem.

If the historians are right, the consequences of Russia’s actions will affect people the world over. Many Americans think they'll only be spectators. We won't be.