Plenty of Vulcans, Andorians etc. serve in Starfleet. However, not a lot serve on DS9 or the Defiant, and we mostly don’t see the crews of other ships. As for the Dominion, the Jem Hadar are bred for war. They are the Dominion’s main soldiers, and the only ones they bothered to send through the wormhole.

Interesting topic!

My thoughts are that these member worlds did not contribute military ships/tech by the 24th century. This may be a bit of a stretch, and not strictly canon, but I believe that the Bajoran Militia was absorbed into Starfleet upon joining the Federation.

Using this same logic, I would extrapolate that any military force other previous member worlds (ie, Vulcan, Andor, etc) would have also been incorporated into Starfleet. I would also argue that this is why the only Vulcan ships we see in the 23rd-24th centuries are transports or maybe a small science vessel (although I can really only recall transports). As opposed to the Vulcan ships with actual tactical capabilities that we saw in ENT. I believe there was even a Federation Starship (the Intrepid?) on TOS that was crewed by Vulcans, which I think is also evidence that they no longer used their own distinct fleet by that point.

Regarding the Karemma, I see this as a similar situation. Yes they had ships but I feel like they represented a non-military segment of the Dominion (weren’t these the guys who were trying to sell Quark a bunch of Tulaberry Wine?). My memory could very well be wrong, but I never saw them as a major military force.

Regarding the Cardassians and the Breen maintaining their own fleets during the War, I would imagine that over time the Jem’Hadar would overrun their empires by force, should they not willingly submit, and that left unchecked, the Cardassians could have had the same standing as the Karemma in the Dominion after enough time.

That makes sense. Thanks.

I think they were evenly matched. Yeah.

I think I've read that Starfleet was more like the military of the Federation when they were at war.

@Captain Jonathan Glover absolutely. While it’s often been pointed out that Starfleet isn’t strictly a “military organization”...it also very much is, and was most certainly as being so during the Dominion War (as well as in the Nicholas Meyer films...David Marcus actually explicitly refers to it as such in TWOK). While it definitely has other functions, largely exploration and diplomacy, with defense being secondary to these, it’s not like the Federation has some other military force to rely on. Starfleet is most certainly the Federation’s military force.