It is basically an Age-of-Sail novel set roughly 1,700 years in the future. There is FTL travel but no FTL communications. If you want a message sent between systems, one or more ships will have to take it. Best speed of travel is about 19 light years per week.
The problem with space is that no matter where you are, every place else is a long way away.
Or, as Douglas Adams put it in The Hitchhiker's Guide to the Galaxy, “Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.”
WWG1WGA
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)