Eternal_Freedom wrote:
Saying that we never see them not armed doesn't mean they are armed, I'm pretty sure that's a logical fallacy.
Which is where we are with assuming they're not-armed too. Which leaves us to consider other factors.
Starbases are, regularly, used as military bases, and have a lot of value. We know for a fact they handle the repairing of armed ships and are where Starfleet Officers go for reassignment and training, they have strategic role of note, and are directly under Starfleet, they aren't civilian ships. We know piracy exists in-universe as do enemy powers, who can attack at a distance from the borders. We know they almost certainly have large power supplies. We've seen the armaments a mining station of a foreign power had- light, but including both phasers and photons as well as solid shields.
Torpedo launchers aren't exactly super expensive things for that matter. There's different levels of them, the top end ones can burst fire and rapid fire and all that, but ancient Mirandas have them, and heck, Runabouts have mini-launchers. Ditto phasers, they're on every class of ship period, and a space station by it's nature is going to have power considerably above most ships. Even a few are strong discouragement at low resources (also do have some other role too, they can be used to clear asteroids, debris, and other hazards that end up in the station's space).
I think the assumption that they don't have weapons is on far shakier ground. We do see other stations with armament and we do know a chunk of their role. The only unarmed ones I can think of are smaller science stations without a starfleet crew.
Also, sure, they probably do have substantial stores or torpedoes and such - that doesn't mean they can actually fire them at enemy ships. That's like assuming, oh, a WW2 submarine tender should be able to fire large volleys of torpedoes at enemy warships just because they carry them aboard.
They don't necessarily have a lot of launchers, but they do have a reason to have some. They have a reason to carry military supplies, and unlike a sub tender, are going to be expected to defend themselves/have reason to use them. Heck, with a lot of them (both Regula and Mushroom styles), they have internal space for ships so even if they had ships for defense, those ships cannot aid in defensive until given time to deploy.
Also- In Emissary (the TNG episode, not the DS9 one), a Starbase fired a class 8 probe containing a person in a Photon Torpedo case. So, we actually have an example of a Starbase firing a torpedo. Additionally this was done because the starbase didn't have a ship available (and indeed, when we visit them there's often no other ships around), so Starbases don't have reason to expect ships to handle defense for them.
The fact that photon launchers are multi-role and double as probe launchers... well, that's very starfleet, isn't it? And gives them another reason for them to have them. They can actively scout nearby systems with those.
Oh, and looking up the probe thing, I found data! In 'In The Pale Moonline,' both Starbase 129 and Starbase 153 show up on the casualty lists. Notably, crews assigned to ships are separate, so that would suggest a high likelyhood the bases themselves were involved in action.