Flying just got a little bit more dangerous. That’s how this moment feels.

I’m writing this on an airplane, looking at the words stitched into the back of the seat in front of me: Fasten Seat Belt While Seated. And thinking of the people found Thursday in that Ukraine field, some of them still buckled in.

Life Vest Under Your Seat, a message informs me. It’s one of those data-points we largely ignore, because a life vest is an item to be deployed in a low-probability event that, for the sake of our flying serenity, we round down to no probability. My operative scenarios for this flight do not include a water landing.

And truthfully, I’m not actually worried on this flight to Texas. I nodded off on take-off, as always. The “flyover country” below does not include any civil wars or separatist movements. (I’m pretty sure the Second Amendment does not cover the right to own military-grade surface-to-air missiles – but I bet you could get an argument in Texas about that.)

Flying is safe, even after yesterday, and even after MH370 earlier this year. But still — this was a horrible and disturbing event, above any beyond any body count. Imagine if one of your friends or family members was on that plane. (Many people today in the AIDS research and activism community are reeling from the news that many of their own were killed, including a beloved leader, Dr. Joep Lange.)

Above the clouds we are supposed to be safe, as my colleague Ashley Halsey said to me yesterday. Looking out a jetliner’s window, at cruising altitude, we can’t see any individual person below – because the people, and all their problems, are reduced by distance to invisibility.

But then Thursday the surface world reared up and destroyed that plane cruising on an 11-hour flight from the westernmost edge of the Eurasian landmass to the southeastern corner. Did the people aboard know they were flying over a conflict zone in eastern Ukraine? From the plane you probably couldn’t tell where you were without a good knowledge of geography or without tracking the flight using a special computer program.

Had they heard of the Donetsk People’s Republic?

As Halsey reports, hundreds of commercial airliners have been flying that popular international route, know as L980, across Ukraine. There is an airspace to the south, over Crimea, that has been closed by U.S. and European aviation officials because of the Russian annexation of that part of Ukraine, but that’s not where Flight MH17 flew. The area in eastern Ukraine with rebel fighting had remained open to commercial aviation above 32,000 feet – even after there was evidence that the pro-Russia separatists had obtained surface-to-air missiles and had downed a military cargo plane in recent days as it flew four miles up.

Question: How many surface-to-air missile batteries are out there, spread across that vast conflict zone that is the midsection of the Old World?

To what extent has the U.S. tried to control the spread of these weapons and get them out of circulation? Yeah, they’re not nukes, or chemical weapons, but you just saw what one can do.

It feels like some barrier has been breached, some safety cushion eliminated. Surely this is keenly felt by international travelers today: The hatred that lurks below, on the troubled surface, no longer feels quite so far away.