It was 100 years ago today that Gavrilo Princip murdered Archduke Franz Ferdinand in Sarajevo, lighting the fuse that killed 10 million people, exterminated empires and nations, destroyed the Enlightenment, and gave us the only world any of us alive have ever known. Anatole Kaletsky reminds us why the Great War happened, and how easily it could happen again.

For one, he says, a “naive materialism” that believed mutually beneficial economic ties and integrated economies made war between the Great Powers unthinkable is with us today. For another, the dynamics of the rise and fall of Great Powers, and the inability of diplomats to appreciate and therefore to safely navigate the psychology of this waxing and waning, is with us today (e.g., our provocations of declining Russia, and the looming threat from rising China). And for another:

Which brings me to the clearest lesson from 1914: the pernicious nexus of treaties and alliances that commit great powers to fight on behalf of other countries. This turned localized conflicts into regional or global wars — and did so with terrifying speed and unpredictability.

The obvious examples today are NATO and the U.S.-Japanese mutual defense treaty, which in theory commit the United States to launch wars against Russia or China if they encroached on disputed territories in Eastern Europe or the East China Sea. Could such treaties act as a hair-trigger for global war, as in 1914?

Consider this statement by General Sir Richard Shirreff, formerly NATO’s second most senior military officer at a debate about Russia: “Everyone surely agrees that we would be ready to go to war to defend Britain’s borders. Well, as a NATO member, Britain’s borders are now in Latvia.”

Yesterday, I heard a recording of an interview the former Iraq war correspondent Dexter Filkins did with Terry Gross of Fresh Air. Check out this portion of it:

GROSS: So in Iraq, Iran is on the side of the administration that the United States helped put in there, but that we’ve now turned against. And in Syria, Iran is on the side of the dictator who the United States is against. So a lot of people are speculating, like, in Iraq are we on the same side as Iran? Do we form an alliance there? Like, what are your thoughts about what this means for American-Iranian relations?

FILKINS: It is one of the great ironies of the American war in Iraq – was that the guys who really got the most out of it were the Iranians. And they have us to thank for that. Yeah, I mean we basically put Maliki in power in 2006, but he has been – he’s really not a friend of the United States. He’s a friend of the Iranian regime. And he has, you know, served their interests, I think it’s fair to say, far more than he’s served American interests. So what does it mean now? I think – you know, a lot of people have speculated that, well, you know, the Iranians and the Americans have a common enemy in ISIS, so we’re going to get together and we’re going to go after ISIS together. You know, I think that’s kind of overstated. Look, the Iranians and the Americans are rivals in the Middle East, and I think they will stay that way.

GROSS: What do you think are the odds that what’s happening in Iraq and Syria is going to kind of blend together into a big regional war that will encompass other countries as well?

FILKINS: Well, it’s kind of already happened, you know? If you just take the Syrian Civil War – I mean it looks like the Spanish Civil War in the 1930s, really. It’s like everybody’s in. So who’s supporting the Assad government? The Iranians and the Russians. Who’s supporting the rebels? Well, you’ve got the Saudis. You have the Qataris. You have the Turks. You have the United States. You have Britain. So that Syrian war has basically become internationalized, but I think what the invasion, I think, of Iraq by Isis has done is it’s essentially – or it threatens to kind of merge those two wars because you basically now have ISIS on both sides of the border. And you have – actually have ISIS in other countries as well. They carried out a huge car bombing in Lebanon in February – a huge car bomb near the headquarters of Hezbollah, who of course is also fighting in Syria. So that’s three countries running, you know, from East to West, all linked together, all basically being pulled into the same war – Iraq, Syria and Lebanon – with all their neighbors involved. You know, this war is already spread. I mean if you look at just the refugee crisis, which is extraordinary, you know, I think the third or fourth largest city in Jordan is the big refugee camp up on the border. That’s not a really sturdy monarchy. It’s causing a lot of problems in Jordan. I think something close to 25 percent of the population in Lebanon is now refugees from Syria. Lebanon is a fragile, tiny place. It’s just not going to last. So the whole region’s getting pulled into this thing. But it basically starts, I think, with Syria.

Impossibly complicated interests and alliances.

Are you willing to risk World War III to defend Japan’s claim to a few rocks in the Pacific against China? How about to defend Taiwan? What about the Baltic nations? You see how easy it could happen. History never ends.