Why didn't the republic have a standing army?

Why didn't the republic have a standing? With all the turmoil in the history of Star Wars, relying on the Jedi alone seems....ill advised to say the least. Was a reason ever given, other than there needed to be a reason for the clone wars?

It was intended to be gesture of unity and pacifism by the post-Ruusan Republic.

An army is expensive especially on the galactic scale, the new sith wars nearly bankrupted the republic so keeping a standing army isn't really feasible when you have jedi that can put the conflict to rest before it even begins 7 times out of 10. Oh and what the guy above me said.

Note there were local defense forces and even a Republic police force, but yea, what the others said.