There are various types of military locations in Vindicta.
The airfields are the main source of strength for the enemy military.
At the start of the game they will all be occupied, and fully supplied.
They are where the enemy can spawn new reinforcements, all other locations must be reinforced logistically.
Every hour or so the airfield can bring in new infantry and vehicles, with the types depending on the campaign progress.
These are large enemy locations, that start with an officer.
Smaller locations. Some of these exist at campaign start, some are created over the course of the campaign as the commander ramps up operations. They do not start with an officer, and must be assigned one from the airfield (see Military actions).
These are deployed by the enemy in areas of high rebel activity.
The defenses at enemy occupied locations are constructed over time.
How much time depends on the size of the enemy garrison. A good estimate is 20 infantry can build a location fully in 12 hours or so.
At campaign start, enemy occupied locations will have various levels of build progress.
If you capture an enemy location you must garrison at least 20 recruits there if you want to maintain its defenses.
If you garrison less then the defenses will slowly degrade.
You cannot increase the defenses just with garrisoned troops, you must build them yourself with the build menu.