“Is the Empire a failed state?” Yeah, probably. When we first meet them, they are trying to consolidate power by massive displays of force, and are dealing with at least one open rebellion. Also, let’s not forget that Han Solo is explicitly a criminal. Until “spice” was bowdlerized, he was explicitly a drug smuggler for a cartel run by a space gangster. Exactly the kind of person who would–if he owned a truck instead of a spaceship–have a scary firearm or two concealed about his cab.

“Is the Alliance a failed state?” I don’t think so. Serenity is very explicitly not armed. They make a point of joking about how yokels don’t know that cargo ships don’t carry weapons in the first half of “Train Job,” and in the movie, they have to weld a big cannon to the top of the ship. The only armed ships I can recall are either explicitly military or explicitly Reavers.

I think the “pirate ship” model is the one that a lot of scifi writers are going for. The idea that you’re hauling valuable goods over long stretches between defensible locations, and accordingly every vessel gets a gun mount or two, even if they never fire them. This tracks to varying degrees of effectiveness, depending mostly, I think, on how “civilized” space is. In Firefly, there are scads of populated planets and moons, and the Alliance patrols between them pretty regularly, especially close to the Core. In Star Wars, there are also lots of populated planets, but lack of effective high-speed interplanetary communication means that getting a distress signal out is slim enough that a private citizen might be expected to take matters into their own hands.