Not comparable unless there is a adversary UN-equivalent developing weapons to use against UN members.
But the Romulans aren't a UN equivalent, or a Federation equivalent. They are an empire. Because of that, the Federation is always at a disadvantage socio-politically, because they have the burden of holding together a trust. They're unity is a vulnerability as well as a strength The point still stands, in that the federation is just that, a group collected for the purpose of having peaceful relations, and some of those relations have a good faith understanding that it can only be the trust that it is, if it can be trusted. Sneak attack weaponry goes against that construct. Espionage goes against it, which is why they hide & disavow whenever they do that too, because they shouldn't be doing it, as it is not operating in good faith, & while some outside influences can generally be considered to be ones you can't have good faith relations with, some, like the Romulans, use the gambit of politics to play against the UFP, hoping they will falter in their convictions, because that's how you topple the trust. If the Cardassians are coming up with bioweapons in Chain of Command, should the Federation be coming up with some to match? Hell no, & the above is one of the reasons why. I'd argue the primary one. My point is that the best course is to play to your strengths, & not your soft spots. Klingons got cloaks, & as long as they can trust you, they got your back when you need the thing anyhow. They stay with the UFP because it is wiser than dealing with the Romulans. Why? Because you can't trust them. Trust is the only currency they have. Why squander it trying to keep up with the dirty dealing?
The UFP is a tighter alliance than the UN. More comparable to the EU, but closer than that too. Somewhere between the EU and the 18th century US.
I would consider the Federation to certainly be a type of empire(many federations are), especially if you defined it by the original Roman definition. It expands by assimilation. This is a form of indirect conquest. All members contribute to the res publica. Humans hold an hegemonic primacy. It controls vast territories, has borders, a large defense force, and fights over those territories with its neighbors.
That’s a bit of a stretch. People join the Federation by choice and retain their unique cultures so long as they meet certain basic guidelines of respect for rights. Expanding by incorporation is not the same as by assimilation. Protecting one’s own territory and establishing colonies on unoccupied planets is not the same as conquering territory.
Nations joined the Roman empire by choice as well. It would have been interesting to have seen a story where 1 or more major founding members attempted to withdraw from the Federation and set up their own independent It would no doubt lead to a war. If the Federation were a real world polity, this would certainly happen eventually. Federation benefits seem to be built on citizenship. The Federation is more than a loose alliance of worlds. It has a central authority on Earth. and it has Starfleet, which is everywhere. I always got the impression that if Bajor joined the Federation, Starfleet would largely assume the roles of the Bajoran militia.
The point is, the UN is not an apt comparison because it does not have to deal with an adversarial entity of similar size or capability. But it doesn't matter what kind of government is on the other side; if there is a threat, it is up to the Federation to address it. Member worlds are not left to defend themselves, that is Starfleet's job, and thus the responsibility for those defense decisions is at the Federation level. Sneak attack weaponry is just weaponry. If it gives an advantage in defending your side, you employ it. If it is going to be used against your side, you counter it. I will point again to submarines using cruiser prize rules in WW1. The Germans tried it and lost quite a few U-boats. They knew that torpedoing merchant ships without warning could bring in the US and lose the war for them. They also knew they would lose if they couldn't use the submarine weapon effectively, so they used it. It's almost an inevitability that whatever weapon can be used, will be used. Everybody hides and disavows espionage, BTW, it's kind of built-in to the concept. If the weapon is a threat to your side, the best way to counter the threat is to develop a comparable capability against the enemy. If you think those weapons are so bad they should be eliminated, the other side doesn't have an incentive to negotiate unless they have a fear of something similar being used against them. Not using the weapons technology at your disposal is creating a soft spot. On the subject of trust, I would say the worlds who rely on the Federation for their defense would trust that organization to develop whatever capabilities are possible to deter or counter a potential enemy. The problem with relying on the Klingons' capabilities—besides the possibility that they don't live up to their obligations—is that they have their own territory to defend, so there is a potential in wartime of their forces being drawn away from Federation priorities.
Again, this was in relation to maintaining the peace. The Federation and Cardassian Union have been at war throughout the 2350s and the official peace treaty was only signed in the late-2360s. He may have been naïve about the capabilities of the Bajorans, but he isn't going to risk damaging relations with the Cardassians for who were deemed terrorists.
For the most part, that's true. What other ways could be done to make Marty Stu Picard look better in the face of the narrative without making anyone look like a twit? (One or two reasons involving an active captain's experience compared to memories from a desk job if it's a new situation, but not for a 43 minute limitation in an episode that has to say tons more... and not for every single episode either. It wasn't too much different to TOS in that regard.) But when the one Admiral spanking Picard over ditching the "Calculate to the last digit the number Pi" with making Hugh not forget his humany-wumany side the course of action, that's the one time that an admiral, when not taken over by alien cooties, wasn't written to be dumbed down to elevate Jean-Luc Stu with... Nah, I'll stick with Marty Stu Picard - that has a nicer ring to it.
Admiral Pressman wasn't clueless, although he was callous. And sometimes "good admirals" can do some pretty low things, like Admiral Ross. And then there's Admiral Cornwell, who was portrayed as pretty clueless.
Ross got the job done, though. Admiral Brett Anderson, on the other hand, was too high minded and his principles got him and many more killed in the battle of binary stars. He wasn't a bad man, and in one of the books its shown that in a different kind of crisis he was very effective, but for this he was the wrong leader for the situation. Another good Admiral was Forrest. He handled situations like the Xindi attack as well as could be done, one assumes, though would he have been good enough for the Romulan War?