I just can't see how Starfleet could disarm after a war. If anything, the demand for ships is greater in peacetime: basically every episode of every series bar VOY is based on the lack of starships, forcing our heroes to act on barely sufficient or insufficient resources.
If anything, planners might breathe a sigh of relief when a war is declared, as that frees them from the contractual obligation to survey, explore, negotiate, settle and so forth, cutting down starship requirements by 70%.
Navies today do basically nothing but fight, which makes them diametrically opposite to Starfleet which is up to its neck in non-fighting duties, so much in fact that it barely finds time for wargames. Perhaps once in a century, it seems...