Charles Phipps wrote:
It's not that hard a concept to wrap one's head around. Starfleet handles the Federation's defense as part of its job but it does a lot more stuff that compromises about 60% of its job. The PD actually makes this possible, arguably. If the USA wasn't involved in foreign wars, we'll....the last war we'd have fought in was WW2.
Which, in addition to being a very good point, leaves one to wonder how an organization like the United States would be able to maintain a military this size without the constant threat of foreign hobgoblins to justify those huge expenditures. If your military hasn't been at war with anyone in sixty years, people start to wonder if they still need it; the the day comes when you find out that you need it, and you find you no longer have it.
Starfleet is the solution to that problem. They ALWAYS need funding, because exploration is always a good idea (and sometimes it can be highly profitable for the Federation). They keep their fleet large and active, they keep their equipment up to date, they keep their crews trained and competent, and providing them with adequate weaponry means that IF something scary happens, they can pull the exploration crews off the frontier and have them dig trenches.
In other words, it's a bit like having a militia composed entirely of scientists. One day Russia declares war on you, and all at once a hundred thousand Adam Savage and Jamie Hynamens report for combat duty at the Large Hadron Collider.
The issue is complicated by the fact that the show is ABOUT Starfleet so we never see Planetary Security for Earth. Also, the "defenses" Earth and other races have which get ignored by V'ger and other groups.
FWIW, the novelization of STID implies that most ground/space combat is performed by "automatics." It's implied that the fighter planes that make a flyby over Kirk's speach are also unmanned drones. In that context, it's a foregone conclusion that one may not actually NEED a standing military to have a competent fighting force; the Earth Government really just maintains an arsenal of automated combat systems capable of defending the planet and can deploy them on a moment's notice without the huge expenses of needing to train and staff an army.