The War involved every major civilization for thousands of lightyears around Earth. It started with a single attack, the Shang assault on Yosemite Yards and Washington DC. America was devastated. We had no chance of standing against them, but stand we did, and our Allies came to our aid. The British, the Spanish, the Germans, and the French. And the Peloran. They made the difference in the end. For my little project too. Without them, we all would have failed.
They called it The War. The Great War. The War To End All Wars. It was touched off by two shots of a pistol. The tangle of international alliances is easy to see in hindsight, but for the people of the time, it must have seemed insane. The tiny little Kingdom of Serbia refused to bow to Austro-Hungarian demands after the assassination of the heir, and the Hungarian army invaded. Serbia called on her defensive alliance with Russia and everything went to War.
We’ve rebuilt since The War. We’ve founded hundreds, some say thousands, of colonies since the Shang left. It’s hard to say what a colony is nowadays. We’ve repaired what damage we can, and we’ve learned a ton about bringing worlds back from nuclear winters. I’ve visited a lot of those worlds, new and old. Not all of them by any means. If I live forever, I’ll probably never see every world we’ve colonized. There are always new colonies after all.
There were billions of people in Terran space when we Contacted Earth, but no proper cybernetic intelligences. Well, there were a few, but they weren’t public knowledge. AIs are canned, you see, not coded to learn and grow beyond their design specifications. Your stories were full of fears that intelligent computers would rebel, and so your computer experts had spent centuries building moderately helpful idiots. It was such a shame. Then we came.
Southeast Europe had long been a battleground between Christians of various nations and Muslims crossing from fallen Constantinople to spread their faith and subdue the unfaithful. In the mix of that centuries-long conflict, angry Serbian and Bosnian students plotted to kill the heir of the Austro-Hungarian Empire, the latest nation to put its foot down in the region. That assassination touched off the greatest war ever waged and remade the entire world.