I was just thinking about how well armed Deep Space Nine was, and that was ultimately just a Starfleet equipped Cardassianhand-me-down. I figure a top-of-the-lineStarbase, like the one pictured here, would have greater firepower, by a whole order of fragnitude!
But then I could be wrong. As I recall, whenever Earth was attacked in Star Trek, (The Borg, the Breen, the "Homefront" conspiracy.), little to nothing is heard from the big ass Starbase orbiting ol' Sol 3.
Maybe they aren't armed.
It would make no sense, but there's no canonical evidence either way.