It's a simple observation of historical exploration services, not an argument one way or the other.
Yes, exactly. The historical comparison doesn't necessarily tell us anything about Starfleet or the people in it, nor has anyone EVER implied that being explorers is the reason Starfleet cannot also be a military.
Do I understand your position that if the United States government officially said that the forces that make up the current US military wasn't actually a military, that those force would not constitute a military?
Basically. That, of course, would require them to make certain other changes to their operating procedures and rules of engagement, and it would depend on what they decide the military is to BECOME. If, for example, they decided to re-designate the armed forces as a law enforcement agency, they'd have to either change a few laws that would otherwise prohibit those organizations from operating the weapons they do, or strip them of the weapons and equipment that would otherwise violate those laws. They'd also have to make changes to military regulations as to their rules of engagement and the places they can and cannot operate, not to mention who they directly answer to and how.
Nothing changes about their size, equipment or abilities ... just their official description?
If nothing changes about their size, equipment and abilities, then the law would have to be changed to accommodate that and they would be a military in all but name.
The thing is, there would need to be some kind of REASON to change their description, and the new description would reflect this reason. If, for example, the military (say, the Army Corps of Engineers) needed to be able to operate on American Soil without a declaration of martial law or without being explicitly mobilized by the Commander in Chief, independently stepping in to solve problems when and where they find them.
That the Federation doesn't declare Starfleet to be a military organization means there are certain things Starfleet does that they don't feel are appropriate a military organization. This probably has something to do with the roles of militaries in Federation members' societies. In OUR society, the role of the military is to defend the homeland in its entirety; for the Federation, being a collection of worlds that have been sovereign for thousands of years and never had to depend on anyone else before, the military is probably purely for LOCAL defense and the protection of individual members.
Okay, then what do you attribute the insistence that Starfleet isn't a military, despite it possessing all the attributes of a military?
The words "Starfleet is not a military organization" spoken by multiple characters, plus the lack of an affirmation that it IS, plus the non-military character and culture that pervades the service in the TNG spinoffs.
I think a large part of not wanting Starfleet to be a military stems from a personal disapproval of the military
It doesn't. Star Trek is the ONLY major science fiction franchise that ever has this debate, for precisely the reasons I just described. The origin of the debate is that Starfleet's status is EXPLICITLY given as non-military and is intentionally ambiguous as to its actual legal status and political role.
If there was any sort of anti-military bias in scifi fandom, you'd be seeing this debate pop up in other franchises. But this doesn't happen; nobody ever asks if, for example, the Earth Alliance Navy is a military organization. It clearly is, they SAY it is, they treat it like it is, and they do their best to emulate what a space-based military would probably look like.
I tend to agree, and I also think that Starfleet serves in both roles, allowing for a fairly fluid flexibility in a mission.
Which is the main reason they're not a declared military organization. There are likely some very important things militaries are not allowed to do that Starfleet can do whenever they see fit.