Sometimes it vacillates between times of war and peace. The gap is usually wider when extended times of peace allow the "war tech" to be developed with the incr

Sometimes it vacillates between times of war and peace. The gap is usually wider when extended times of peace allow the "war tech" to be developed with the increased funding and secrecy allowed by peacetime. Sometimes it vacillates with general tech advancements. Tech driven by large bureaucratic structures will still occasionally fall behind what's available on an open market driven by competition and the public's bias toward cheaper goods. In other words, as a country's general economy goes, so goes its war chest... unless it manages a quite large war chest, in which case it can attempt to conquer another country and pillage the economic spoils of that country.