There has been something that has bothered me for some time with Star Trek: the idea that Starfleet is not a military organization. It's shown up in The Next Generation more than once, in Enterprise, and in the first J.J. Trek. I didn't watch Discovery, as I deemed requiring a pay channel as a hidden tax on Trekkies. And nothing I've heard suggests I wouldn't throw a remote control through my TV if I did watch it, so we'll skip that one. I have not seen Picard yet, but I have watched this trailer. And if it turns out that Picard left Starfleet because he suddenly realized it was a military organization I'll quit the entire series then and there.
It is a small nit to pick, but as this strange perception increases so it does as well.
Because the truth is that Starfleet is, and always has been a military organization. The original series made no bones about it. If you'd like to read a small essay on the exactly what a military organization is you can click here. (No that's not a link to another of my posts; its a Wikipedia article) But, in essence, the purpose of a military is to protect a polity from external threats. Militaries can perform many other roles such as: mapping, exploration (okay not recently), humanitarian aid, emergency construction, evacuation, protection of diplomats, and the list goes on. But, its primary function is protection.
As it is with Starfleet. We've seen multiple episodes where they engage in these very same functions. But, at the end of the day, when there's an external threat to the Federation, Starfleet springs into action to stop it. Because its primary mission is the defense of the Federation (a polity) over all else. Here are just a few episodes that show this:
TOS
In 'Errand of Mercy' Starfleet musters its fleet to meet an anticipated Klingon attack force. By the end of the episode Kirk and Kor wait expectantly for news on the battle they expect these two fleets to be fighting. In 'Balance of Terror' its made ultimately clear that Starfleet is solely responsible for the defense of the Federation. It maintains listening posts along the Federation-Romulan Neutral Zone. Kirk spends most of the episode attempting to destroy an invading Romulan craft. In 'The Ultimate Computer' a new AI command computer is tested in a series of war games to determine if its efficiency is better than a human being's. While there is one other test involved, the focus is clearly on its tactical prowess.
In 'Star Trek 6' at the prospect of peace between the Federation and the Klingon Empire (its principal rival throughout the original series), one admiral asks 'are we planning to mothball Starfleet?' suggesting that Starfleet's primary purpose is to defend the Federation. TNG
In 'Peak Performance' the Enterprise D is engaged in war games designed to ascertain their ability to defend the Federation. In 'The Enemy' it is made clear again that Starfleet is responsible for ensuring the integrity of the Federation-Romulan Neutral Zone.
In 'The Wounded' we discover that Starfleet defended the Federation against the Cardassian Empire in a previous war.
In 'Suddenly Human' we discover that Starfleet had fought a war with a race known as The Talarians.
In 'Yesterday's Enterprise' it is made abundantly clear that Starfleet is the main defense force of the Federation. Some may point to minor differences such as ship layout, but it only makes more sense for a polity at war to create ships more focused for that endeavor. Starfleet also started designing and building warships (aka: The Defiant Class) after its encounter with the Borg. In 'The Best of Both Worlds' Starfleet ships are pulled from every assignment to attempt to defend the Federation at Wolf 359. Okay, not successfully, but it's like Christmas: it's the thought that counts. In 'Decent' Admiral Nechayev makes it clear that the security of the Federation overrides all other considerations, while discussing why Captain Picard failed to implement a virus that could possibly have destroyed the Borg. In 'Chain of Command' it is again made apparent that, should a new war break out between the Federation and Cardasia, it is Starfleet that will fight for the Federation.
In 'Star Trek First Contact' ships are again recalled from other missions to defend against a Borg incursion.
DS9
In 'Homefront' it is made clear that Starfleet is the primary defense force for the Federation. They even gain the power of Martial Law for a short time. (too bad no one listened to the warning this episode tried to send 2 years before 9-11)
In 'The Adversary' we learn that Starfleet had previously fought a race called the Tzenkethi.
In 'Nor the Battle to the Strong' it is shown that Starfleet is defending the Federation in both ship to ship actions and ground battles.
Nearly every episode in seasons six and seven of DS9 support the argument that Starfleet is the Federation's Military branch.
Voyager
Due to the nature of Star Trek Voyager only the final episode shows that Starfleet is the Federation's defender. In it we see several Federation vessels used to defend against a Borg incursion.
Enterprise Star Trek Enterprise takes place before the founding of the Federation, but even then Starfleet is still Humanity's defense force. It destroys the Xindi probe that attacks Earth. It Defends the solar system from Duras as he attacks Enterprise. And Starfleet's only warp 5 ship is recalled from its exploratory mission when Earth is attacked.
These are, of course, only one fragment of the evidence that Starfleet is a Military organization. On top of all this, they have a military rank structure, including similar codes of conduct and courts (such as courts martial). I cannot say where the concept that Starfleet isn't a military came from; I can only imagine that someone fairly high up in Paramount forced this ludicrous concept onto the writers. I'd speculate that whomever is responsible simply doesn't like militaries in general. I'd wager they see military personnel as 'murderers, rapists, and people who can't get a real job'. But they like Star Trek. Ergo Starfleet cannot be a military organization for, if they liked a show about a military force (particularly one that performs many of the same functions as the military of the country that birthed it) they might actually have to reevaluate that opinion. Better to just try and redefine it. It's a small nit to pick, yet I feel so much better having scratched it.