Someone needs to write a stroy about how the Republic came to being and list some MAJOR events that would've slowed scientific research down. I mean, today on Earth we are only about 20 years away from the cure to aging, and I asure you that if man kind wanted to create the Death Star or something very similar within a 25,000 year period, they would certainly do it.
Perhaps the issue is not as technological; however, as it is political. Killing billions becomes alright after a couple thousand years just like pro choice or pro life abortion? Maybe, and that could explain some 3-4 thousand years. Give war a maximum 10,000 years(based on about how many major wars Earth has had in a 250 year time span which is about 2 per century). There are still 11,000 years left. Any thoughts?