So some background so that you’re caught up:
In the world that I’m working on now, in 2005, the deadliest plague in history struck the world. The Black Flu as it was called caused havoc and destruction across all six inhabited continents, killing over 5 billion people by the time the Black Flu burned itself out in 2010.
Anyway, on the East Coast, the skeletal remains of the United States Government under the leadership of President Barack Obama exit Mount Weather and return to Washington, DC where they clean up the District of Columbia and through the hard work and effort of everyone, DC became one of, if not the, most fortified and powerful areas in all of North America.
When Obama was cleaning up the area, Obama made drastic changes to the scattered and tattered US military. Obama decided to disband the old US military and restructure it as a new single, unified force call the United States Garrison due to overlapping and redundant operations as well as pride being needed to be restored in the military.
Anyway, onto the question; how big should I make the US Garrison?
So far, in the current year of my world (2025), the District of Columbia (which has expanded its borders to the surrounding counties) has a population of 450,000 citizens. I was and still am playing around with numbers and I’ve decided to make the US Garrison 75,000 Troopers-strong, or about 16.5% of the DC population. The Garrison is a professional active duty military and was created with the idea of creating both a military force that will fight the enemies of the United States while also preserving internal security by acting as gendarmerie force within DC. The Garrison has to contend with fighting against bandits and marauders but they also have to deal with larger rivals that either don’t exactly like the US Government and/or want to become a part of the United States once again. The largest rival to DC is the Virginia Federation, which is based in Richmond and has 390,000 people.
I’m curious, is this too big of a military force? Please keep in mind that this is under post-apocalyptic conditions kind of like The Last Ship and TC’s The Division. How would post-apocalyptic conditions change things up?