I get a sense that by the time of TNG, most Federation member planets are a bunch of freeloaders. It's the humans that do most of the work.
They don't really start building warships until they realize how dangerous the Borg and Dominion are.
That was one of my impressions-- that the Federation may be a little bloated. A lot of member planets that barely believe in building weapons or ships.
Betazed having obsolete planetary defenses in "In the Pale Moonlight" comes to mind.
Not to knock how strong the Federation is, but it is a possibility.
Knight Templar wrote:
Yet for some reason, the Romulans are definitely considered a threat by the Federation in TNG.
They feared going to war with the Romulans.
Not really. In "The Defector" Admiral Haden speaking over subspace to Captain Picard regarding the Romulans.
"No one wants a war. But we are prepared to take them on."
The sense I've gotten from various TNG episodes suggested the Federation worried about going to war with the Romulans. Especially the second and third seasons.
One is signing the treaty of Algeron to avoid further war;
PRESSMAN: That treaty has bound our hands and given the Romulans a tactical advantage for sixty years. I was
simply trying to level the playing field.
Picard: "Is it a Romulan plot?" "Is it a ploy to start a war?"
Quotes like that suggests that the Romulans were the super villains of TNG, besides the Borg.
Another example. the Cardassians were considered a minor power (depending on who you ask) but the same admiral later says: "the Federation is not prepared for a new sustained conflict" --with the Cardassians.
Sometimes I think how threatening an enemy is, depends on who's writing the script (and the series).