For my random historical military fiction fix, I’m reading Gunka no Baltzar. It’s set in 18th century Europe (with country names changed), and the main character is an aspiring Weiben (which is all but Prussia in name) officer who’s sent to become an advisor to a neighboring country’s military academy.
Balzer, the aforementioned protagonist, encounters friction and resistance due to Baselland’s backward military doctrine and organization. There’s some political intrigue, but thankfully not too heavy to detract from serious military reform. This may be a story in peacetime (at least for now), but I like how it deals with the necessity of a nation to have the means to defend itself, without falling into the disease of self-serving, wishful pacifism.
The art is strikingly detailed, and the setting is well-researched. Oh, and there’s some valkyrie cosplay, too! At five chapters scanlated, this manga is fairly new, but it’s worth your time if you’re fond of historical militaries like me.