Athens/Sparta

The one thing im really curious about is Sparta. In the long run, without the Pelopnessian War, i could see Athens being a succesful nation for years and years to come. Sparta, though, intrigues me because they had to realize that being a militaristc state like Sparta was, isnt a good long term option. Did Sparta maybe see the Peloponessian War coming, thus they prepared for it, or did they really have no future plan. Cause i cant see a civilization lasting years and years in a solely militaristic state. I can also see how this idea could be totally irrelevant to anything, and if so, Mr. Shrinsky, anyone, tell me if this idea is erroneus.

Alex