Yes, I remember Warp War - a neat pocket game from Metagaming. A very nice and simple design, yet interesting to play and including ship design and so on.
One way to make warp points unstable is to jam the random event list full of warp-point closing events, and then turn up the event chance per turn to 100%. Still, this will only close one warp point per turn in the whole quadrant. If it's a no-warp-point quadrant, though, this will be somewhat close, depending on how much creation is going on. You could also make Close Warp Point a very cheap component (or even a built-in ability of all ship hulls).
An psychotic solution would be to design a modded AI that does nothing but generate ships that have no property except the ability to close warp points... but that's er, silly and would be a lot of work and have issues...
PvK