It's a tough call, made even tougher by the mishandling of the whole Maquis thing. The concept was interesting, and there were some great eps centered on this plotline, but the whole "Are they still UFP citizens or aren't they?" continuous flip-flop kinda made it harder to parse the whole thing out. I sympathize with the Maquis, but given the larger interests and responsibilities of the UFP government, it's hard to argue with the idea that they shouldn't let one small group of colonies derail something like a peace treaty. At the same time, I could never shake the feeling that it couldn't have been that
hard to just redraw some of the lines so that none (or at least fewer) of those planets had to switch hands at all, while still accommodating whatever both sides wanted from the treaty as a whole.
But assuming that they couldn't, for whatever reason... again, the problem is the citzenship thing. They said in "Journey's End" that they'd have to give up being UFP citizens. This makes sense. Essentially, they are becoming their own little nation, one that happens to exist in Cardassian territory. Yet so much of what went on after this ep with the DMZ/Maquis plotline seemed to indicate that they all WERE still citizens, and that a big part of the tension was the possibility that they could drag the Feds back into war with Cardassia if not stopped.
Finally, while the Maquis themselves need to take their fair share of blame for what went on, and went over the line sometimes (fortunately the "cloaked missiles to Cardassia" thing was a ruse, but if it had been real,
all sympathy would have gone out the window), I will say this: given that part of the arrangement apparently was that the Cardassian
government was also ok with these people being on these planets in their territory, any Cardassian that enters one of those former Federation colonies uninvited with the intent to cause harm deserves whatever fate he receives. Whether or not the Maquis stepped over the line doesn't change the fact that those "rogue" Cardassians had no right to harass and attack those colonists, which they clearly were doing.
This is the mistake I think a lot of Trek fans make. The Cardassian are not, repeat are not, weaker than the Federation, they can't be.
No mistake. The Federation is considerably more advanced technologically, and any one-on-one combat situation between a Federation starship and a Cardassian warship heavily
favors Starfleet. Of this there can be no doubt.
The evidence is the TNG ep "The Wounded." There were two different instances in that ep of a Federation starship taking fire while their shields were down,
and then effortlessly pasting their Cardassian opponents. Both of those opponents were warships (the one that attacked the E-D was clearly Galor-class, and the one that attacked the Phoenix
was identified by Macet as a warship).
These two interstellar power fought for decades, the Federation didn't in that time roll over the Cardassians. If the Federation were superior in technology and numbers at the very least Starfleet would have destroyed the bulk of Cardassian military starships. Obviously they did not.
Numbers? Perhaps not. The Federation is big, and certainly has a higher gross population than the Cardassian Union. It follows that Starfleet would be pretty large as well, but UFP citizens have a LOT of varying interests and career paths open to them. Whereas in Cardassian society, a rather ridiculous percentage of their population seems to serve in the military in some
capacity. So the Fed's numbers advantage might be very slight, if it exists at all, especially if the Cardies were pouring all of their military resources into the war, and the Feds weren't.
Yes, that's all speculation, but that's part of my point: we must speculate about the nature, length, and severity of the Fed/Cardie war, because no on-screen dialog or flashbacks or anything ever gave us a clear indicator of what it was really like. Whereas the superiority of Federation military technology over Cardassian military technology was clearly and unambiguously laid out in canon. So the only thing we can do is speculate and come up with fan theories about why
the war lasted for so long (and why the treaty is so two-sided and treated as so important), despite that superiority.