As often happens necessity overrules everything else. Starfleet is a military when it needs to be one. Hard lessons to learn, the Vulcans tried to warn them in their own way.
Well there was clearly a separate military service at the time as that's where the MACOS came from with the "are you sure you're comfortable with the military being onboard". We never really hear about a separate military force after that, so my guess is they were absorbed into Starfleet and as a result Starfleet picked up a formal military function..IE Colonel West in TUC, what are clearly Starfleet Marines/Infantry in the Siege of AR558, etc
Yep, which is why Picards "starfleet is not a military organization" falls flat and is more of GR's silliness. It could be reasoned that Picard was meaning that Starfleet was not *primarily* a military organization.
That is another retcon. The Earth-Romulan War really ended up being the Federation-Romulan War. Because it doesn't seem to happen until after its formation.
But who was their space navy? Someone had to be protecting the Sol system and Earth in some form or another. MACO's come across as an infantry force.
It has all the trappings of a military without being directly called as such, otherwise it would not be able to react fast enough to threats. I have never had a problem with it being one, does anyone really believe you can attempt to create a Utopia and not have to defend it. Starfleet is essentially a Space Navy which is why there are Admiral ranks rather than Generals. The Maco's were the ground forces which ended up being rolled into Starfleet at some point. They were given Red Shirts to wear, they should have refused them for their own good.
I saw them as more or less being akin to the US Army's old Delta Force, Rangers, etc. Not quite special operatives yet more than just your garden variety infantry. As to who the United Earth Space Navy? Good question. We know the Royal Navy, or at least likely so, still existed as late as 2117 since Malcolm didn't want to serve on a seafairing vessel due to hydrophobia.
It wasn't in the Theatrical cut but was included in the VHS, LaserDisk and pre-2009 DVD's and they were integrated into the movies and not add-on special features. And it was clear. There is a separate military force during the Enterprise time and there are Starfleet/Federation infantry in DS9 during the Dominion War. The canonical status of Colonel West is up for debate.
Some Starfleet people sometimes conduct ground operations, yes. O'Brien took part in such missions. But there is really no evidence for any dedicated Federation 'infantry' or 'marines' after MACOs were disbanded. Ground assignment is just one of the myriad missions Starfleet personnel may undertake.
In TMP - the new Engine design was screwed up, and took Spock showing up to fix it, and they went to a cruising speed of Warp 7 right after. All through TOS cruising speed was Warp 5 - 6 and Max speed stated as Warp 8, with Warp 9 possible for short periods. TMP didn't do anything to retcon the scale. In fact it upped cruising speed from Warp 6 to Warp 7.
^^^ But that's teh thing - What became the design for "Worf" and other TNG Klingons DID not "look exactly like they did in the TOS feature films - ESPECIALLY not how they appeared in ST:TMP). Please look at Row 2, Column 1 and compare Row 2, Column 2 and then to Worf at Row 3, Column 5 and tell me "they're exactly the same..." Please tell me where/when TNG stated on screen that it was a "different warp scale" (not some non-canon source as WE ARE discussing 'canon'. And even if it were how do you explain that the 'new' scale is soooo much slower?
I think StarFleet needs to stop shifting waffling around from teeter totering between Scientific Explorer / Military and just be 50% of each and admit to that. When the going gets tough, they need to be able to fight. When they're not in imminent danger, they can revert back to Science mode and study whatever they want. But just don't forget that both sides of the Scientific Explorer / Military Force need to co-exist like the Yin & Yang Symbol.
They looked exactly like the last time we saw Klingons before TNG...which was STIV. So there's no problem there. The new scale isn't slower. That's just your conjecture. There was a warp scale in TOS, and a different one in TNG. No one needs to 'canonically' spoon-feed that to me. It's no different than the different types of stardates Trek has had over time. Again, that's not a retcon, just a logical change over time.
Its already the case which is why you can see arguments for and against it being a military, as far as I am concerned it has all the trappings of a military force with considerable thought given to exploration and scientific endeavours. If it wasn't a military there would be no need for some to argue that it isn't. Some classes of ship lean more to one than the other depending on their overall size, available space and design goals. Its not really by choice, its a question of necessity due to all the other races having heavily armed ships themselves. Its a lesson they learned very early on as shown in Enterprise.