Starships were defending Earth (providing the planet's defense) in First Contact. They were not in deep space.
They came from deep space, though - all the way from Typhon.
There is no prima facie reason why starships may not be considered part of planetary defenses. For that matter, there is no reason why planetary defenses may not be entirely comprised of starships.
True. But the fact remains that fleets of starships have never been witnessed directly defending planets. The only case where a fleet of starships did show up next to a planet was the tail end of a running battle where at least two ships, the
Defiant and the Admiral's ship, were "original players" and none were indicated to have joined the fray at Earth.
If anything, this appears to be the exception that proves the rule, because spaceships are elsewhere shown as the players (defenders/aggressors) in planet engagements.
But again the thing is, they are
not shown as defenders, ever. They are aggressors - but only in the hundreds, which indicates that aggression against a planet is always met with the sort of resistance we saw at Chin'toka. Otherwise, a handful of ships would quickly slag a world, as seen in "The Die is Cast" - or a single ship would do that if given enough time. A fleet of mere dozens is described as being incapable of actual military aggression in "Redemption". There must be parity of technology there for the Feds, Klingons and Romulans alike to use the same doctrine against the Cardassians. This is not asymmetric warfare, it's merely one side of a symmetric doctrine.
The very fact that warfare still exists in Star Trek stands proof to the single starship (or a formation of two dozen) being negated as an offensive weapon. Since the starship's offensive capabilities are well demonstrated, corresponding defenses must be postulated, then.
Whenever Enterprise comes dashing home Earth's defenses have either collapsed like a house of cards or are being conducted by ships.
Three counts of the former (although in ST4, the thing coming home was the
Bounty), one count of the latter. Other times, Earth does not come under attack, nor do our heroes come dashing home. In two of the former, said collapsed defenses include no collapsed starships in evidence anywhere near Earth. In the remaining one, starships are launched in what doesn't appear to be a last line of defense, but rather a last-ditch attempt to let the ships escape destruction...
It did if are a "carbon unit."
In "The Changeling"? No, it didn't - Nomad was stopped long before even starting towards Earth.
Lots of things get mentioned. The action is in use.
About 90% of Star Trek is talk, for obvious reasons. The
use of planetary defenses was mentioned often enough.
A random moment where they left the planet undefended?
How many random moments like this are there each month?
Probably dozens. After all, the planet would only be undefended if the enemy moved in at greater than anticipated speed, so that defenses could not be mustered. That was clearly the case in TMP and "BoBW": Klingons or Romulans could not have achieved the combination of speed and unstoppability, but would have been slowed down enough to get ships arranged into a defensive measure of some sort.
And if Earth had defensive fortifications or other non-starship assets (as explicitly stated in both cases), the low numbers of ships within a few hours' travel would be of even less consequence.
What is a conventional attack in science fiction? We aren't talking about nukes vs. smart bombs here. Earth's Defenses should be designed to meet the unconventional threats of Borg and Klingon and Romulan and so on.
"Conventional" would be the use of those classic killer starships. As seen in DS9, such attacks are indeed nicely defended against, and even the attack of a very large formation is practically suicidal in two onscreen cases out of two.
"Unconventional" would be V'Ger, Whale Probe or Borg Cube, or a ship out of time such as the
Narada: an unimaginably fast and invulnerable intruder, against which no defense might exist no matter how much the heroes wished, prayed or cursed.
"Unconventional" would also be a hyperjumping death star such as the Xindi one. Vulnerable to all but primitive 2150s defenses, perhaps, but a different beast from the classic starship nevertheless. Earth's defenses probably are capable of handling that sort of attack by Kirk's time, simply by blowing it out of the sky before it hurts Earth. But that's with a century of head start. On the Borg, the Feds had none (V'Ger had been invulnerable but not
that fast, ditto for the Whale Probe, and one assumes they'd still remain invulnerable to 23rd or 24th century weapons).
Tell me more about the Breen attack. I am unfamiliar with the relevant particulars.
What we learn from "The Changing Face of Evil" is that the Breen announce their joining the Dominion War by sending a fleet against Earth. From Starfleet side, we hear that Starfleet Headquarters were targeted, and several buildings and personnel there lost, but that the attack force was mostly destroyed. From Dominion side, we get confirmation that most of the force was indeed lost, but that nobody seems particularly concerned, suggesting it was a Doolittle Raid done for the news value.
Visuals show San Francisco pockmarked with supposed Breen weapons, in what must amount to the wimpiest starship attack ever witnessed in Star Trek. Nothing is shown of the nature of the defense, except that it worked, against a surprise attack (perhaps made possible by cloaking, but not explicated as such).
The astronomical coincidence would be that these systems fail so often and that Enterprise is the only ship in range.
Indeed, these systems fail so often that functionally we can say that they don't really exist and that the Enterprise (functionally) is the Earth's main planetary defender.
The systems don't "fail" - they are defeated. And the
Enterprise doesn't save they day because she'd be undefeated - she sidesteps the enemy and wins by a cheat that in two cases out of four is only made possible by the preceding efforts of the systems.
Federation not allowed to cloak anything basiaclly.
But if dem's invisible, how can anybody tell?
Timo Saloniemi
I would have loved to have heard that on screen.