Ok. In brief: more than a century of tangled alliances and a dying empire has errybody lickin they chops over all this shiny land that was just... Right there. All you gotta do is take it. You got Russia ruled by one of the most profound idiots to ever rule a country, Germany ruled by one of the other most profound idiots ever to rule a country, and Austria-Hungary ruled by the last gasps of the Hapsburgs.

Anyway some thugs did a Cohen Brother's movie about Franz Ferdinand, the younger brother of the emperor. As it happens he kind of thought the people were important and wanted to do right by them, and also his dad hated him for not marrying his cousin. Anyway he dies.

The next 30ish days are another Cohen Brother's movie. I'll try to summarize. Kaiser Wilhelm gives Austria a blank check to start a fight, then goes on vacation. Austria sends a list of demands to Serbia, who delays until they can get some back up from Russia, and ultimately capitulates on all but one demand. A bunch of shit happens over the course of 3 weeks, when the Kaiser gets back he's like "the fuck, I said go to war mother fucker." At some point this could have been averted with a phone call but as it happens, a phone line did not exist between the two cities in question yet. Anyway, Russia starts "mobilizing" and then everybody loses their damn minds and actually mobilizes. To which, Russia formally mobilizes.

Up to this point, war was a formal affair, where you could dig in, stand in a line, and shoot. However between the last major conflict and this one, two things happened.

Somebody discovered a way to make cannons out of steel, and then sold those much more powerful weapons to literally every country that would ultimately be involved in WW1. (Previously they'd been cast in bronze. Steel was too brittle. The story of the motherfucker responsible is quite interesting.)

and somebody else invented man portable weapons that fired continuously, and sold those weapons to every country involved.

So now when you get a bunch of guys in a line and have them shoot, instead of a handful of them dying and the rest running away, everybody dies.

In 18 months all of the armies in Europe were depleted, to the point where a cease fire was called so they could get more guys for the meat grinder.

Anyway, a stalemate eventually emerged. Germany was doing ok, but it was clear that this was going to go on for a WHILE. The US decided she wanted to participate in the military industrial complex that the cannon guy from before invented, and started selling weapons and ammunition to the British. But like, under the table. And also like, not very quietly.

So the Germans started targeting American ships they thought were carrying weapons. One of those ships happened to be a passenger vessel that was absolutely carrying ammunition. But, sinking it turned public sentiment against Germany, (this was a major contributing factor in prohibition becoming law) and the US entered the war. By virtue of having more dudes on their side, and not through any particular action or technology brought by the US, this turns the tide of the war.

Wilson, the US president, had this whole plan for a post war clean up that might have worked. But he had a stroke, and his wife kind of ended up running the country for a few years. (This would lead to women's suffrage.) So the league of nations and the 14 point plan kind of went out the window, Germany got stuck with the bill for the war that Austria started with Russia (who backed out after murdering the Tsar and his entire family in a fuckin' basement).

The engineered post war collapse of the German economy would go on to have no consequences whatsoever.

Also this entire experience would lead to the Lord of the Rings. A book about children walking in to a hellish landscape for reasons they do not fully understand but generally agree is necessary.