system
Given the following post, respond as if you're commenting on Reddit:
human
[Starship Troopers Cinematic Universe] How did the Federation become a galaxy spanning presence with such a limited force projection ability?

They have seemingly endless fleets of starships, but their only ground presence lies in lightly armored infantry with no vehicular armor and limited close air support. Is this simply a case of becoming so dominant that they no longer needed tank divisions?
gpt
Well, until the Bugs were found there was simply no NEED for anything else.  The Federation hadn't run across any other intelligent species in the galaxy and the AQZ was set up to keep law abiding citizens away from what, at the time, was only a possible threat.

Before Buenos Aires was hit all that was needed was essentially a police force.  There was simply no need for vehicular armor or air support.  When the strike came the Federation Council had to act quickly to attempt to prevent another strike.  What forces were available were what was sent.  Along with the decision to proceed directly to Klendathu the lack of any armour or air support reserves were a direct contributor to the previous Sky Marshall stepping down.