(Based on a throwaway line in Alex’s Crapsack universe thread.)
One of the stupider episodes in Star Trek: TNG focused on environmental damage done to the fabric of space caused by warp drive. The episode claimed that eventually subspace would be so eroded away by FTL travel that warp drive would be impossible and the Federation would become unable to use FTL drives or communications. I thought it was a silly episode at the time and Voyager was quick to show a way around the problem.
What happens if that happened to a real interstellar civilisation?
Maybe you start having dead zones – areas where warp travel won’t work – and then the problem becomes a whole lot worse. Entire regions might become impassable, trapping entire planets in the slow zone (see Zones of Thought.) Maybe some AIs can’t function because their computer networks exist in subspace…
What could we do with this idea?
Chris
The Chrishanger 
What could we do. Well my brother started a free game website, seeds of humanity. It flopped. But his idea was that the FTL system did in fact (not destroy) but tear or overload hyperspace. And humanity was scattered. Each world went its own way. Each a new seed if you will.
There was an alien race that came and harvested a bunch of worlds and gave the final kick that destroyed the old FTL network. Kind of like the shadows/vorlons of B5 they came in towards the end and harvested a bunch of worlds, and made sure the new race on the block was stopped from gaining critical mass and reaching the point that it could challenge them
Then a thousand years later one of the worlds discovered a new means of FTL travel. Not the old FTL system. And it starts to spread. This break in the Harvester pattern isn’t spotted right away because the old FTL system shouldn’t finish regenerating for another (insert unknown time frame) The new system spreads and each world is now competing with all the others. Its a time of wild wild west, with the unknown threat of the Harvesters looming over them.
Some of the seed-world had word from the old Comstat network, before it too was destroyed by the harvesters, that worlds were being attacked and destroyed but then everything went silent. REcords were lost, and what records they did have, could have referred to a strange human fleet. Obviously the surviving worlds weren’t destroyed.
We could follow a world or two, and their top individuals. Trade, Government, Military Fleet as first they struggle with others and even eachother, trying to carve out a series of tribute worlds and keep themselves from being dominated by others. Sometimes this is done out of a desire for empire, others, out of sheer self defense. Conquering those that attacked you, and building an indepth defense.
Later all the minor interworld feuds are pushed to the side as the Harvesters show up and its a battle to the death, after this strange alien race, decides to genocide humanity. Anything that breaks the pattern is a potential threat to their domination of the galaxy.
The Deposed King
Cool thoughts. I’ll have to work them in somewhere.
Chris