Does Starfleet accept the use of cannon fodder in battle?

Question

In the DS9 episode "Sacrifice of Angels," during the Dominion War, there is a massive Dominion/UFP Alliance battle. In one scene, as the two sides clash, a pair of Miranda class ships are seen gliding through, then very quickly getting destroyed. One is lanced by a Dominion ship's energy weapon, and another is literally sent flipping with a single torpedo. Of course, out-of-universe, this was done to wow the audience and maybe add a sense of drama and loss. In-universe, it was a demonstration of the Dominion's firepower. It clearly showed how weak the Miranda class was compared to all the other more advanced ships from both sides. It also made me wonder if there was truly a point in sending those two ships out to their certain demise. Objectively, those ships held little sway over the outcome of the battle--as illustrated in the scene mentioned above. The crews of those ships could have been spared if Starfleet had not sent them out. And Starfleet should have been well aware that Mirandas were not sufficient to counter Dominion firepower.

There are a lot of Mirandas seen in the Dominion War. I understand that Starfleet/the UFP Alliance has to use every resource it had, but is Starfleet this desperate? Can't Starfleet put them at the back to provide the critical last line of defense? Instead, they are usually on the front line, where they draw fire and get blown to bits in an instant...

Starfleet performs important militaristic functions when there are threats against the Federation, but unlike a military, its purpose is not militaristic. A military will do anything to achieve victory, and that (somehow even today) includes using cannon fodder. Many other races--for example, the Klingons (who are overly eager to die)--the Romulans (who will do anything for their own benefit and preservation)--and others--are willing to sacrifice their own kind, but Starfleet is supposed to have a moral obligation to everyone, including those who work for it.

Is Starfleet willing to sacrifice its own ships and crew "for the benefit of the many" as possibly indicated by the title?

Answer 1

As below, so above (an argument from what command entails at the lower levels being applicable to the higher ones).

From Thine Own Self, Next Generation. Counselor Deanna Troi takes the Bridge test unsuccessfully several times and is back in her quarters mugging-up on specs. and regulations:

(doorbell)
TROI: Come in. Would be routed through the port transducer matrix. Come to give me more encouragement?
RIKER: No. I'm actually here to tell you that I've decided to cancel the rest of your test.
TROI: What?
RIKER: I'm cancelling the test.
TROI: May I ask why?
RIKER: You've taken the Engineering qualification three times. You're no closer to passing.
TROI: Well, then I'll take it four times, or fourteen times, or however many times are necessary for me to get it right.
RIKER: Deanna, this is nothing personal. Not everyone is cut out to be a Bridge Officer. I don't think this is for you. [...leaves]

After disappointment, a moment's thought; inspiration hits:

TROI: My first duty is to the ship. The ship!

and she rushes to the holodeck:

TROI: Computer, load Bridge Officer's test, Engineering qualification section one.
COMPUTER: Computer ready.
TROI: Run programme.
WORF: The control system for the primary containment field is not functioning.
LAFORGE: Something's severed the ODN conduit between here and the antimatter storage deck.
TROI: Geordi, could you repair the ODN conduit if you went into the crawlspace?
WORF: Sir, that crawlway is in a warp-plasma shaft. He would never survive the radiation.
TROI: I know that. Geordi, could you repair the conduit?
LAFORGE: Yeah, I think I could.
TROI: Then do it. That's an order. (Geordi exits to the Jefferies tube)
[The real] RIKER: End simulation. Something told me you wouldn't let this go. Congratulations. You passed.
TROI: That's what this was all about, wasn't it? To see if I'd order someone to their death.
RIKER: That's right.

Just as a bridge-officer would be expected to sacrifice a crew-member for the greater good and crew members would be expected to oblige, so fleet admirals would have passed through command of a starship on their way up the promotion ladder. No doubt at the stage of fleet command, they would be prepared to sacrifice a ship and captains would comply. This could easily be without an explanation which would make any sense to the crew being sacrificed, as the bigger picture may only be seen from above.

In response to comments (Valorum).

Additionally a mentions must go to Pickard's attempt to slow-down Shinzon's approach to Earth in Star Trek: Nemesis by ramming the Enterprise E into his heavily armed Flagship and Janeway's ramming of the Krenim time-ship in The Year of Hell, Kirk's father in the Kelvin timeline ramming the USS Kelvin into the Romulan ship. Then there's the (this is a good day to die) stylings of Worf attempting to ram the Borg cube with the Defiant in First Contact - it's clear that sacrifice is a part of the ethos of the fleet and it's officers training and sense of honour and duty.

Answer 2

I think Jiminy makes a fine point: when you join Starfleet, you accept the risks, including that you might not come back (and you might even be ordered to your death). But there's another angle here

There are a lot of Mirandas seen in the Dominion War. I understand that Starfleet/the UFP Alliance has to use every resource it had, but is Starfleet this desperate? Can't Starfleet put them at the back to provide the critical last line of defense? Instead, they are usually on the front line, where they draw fire and get blown to bits in an instant...

That's not necessarily what's happening here. You're missing something important: that Starfleet watches out for their own. Consider one of the more dramatic scenes from Star Trek VI. The Enterprise is being hammered by a Klingon bird of prey that can fire when cloaked. Sulu knows they need time so he offers the only assistance he can: he draws Chang's fire.

SULU: Shields up! All right, now we're giving them something else to shoot at.
LOJUR (OC): Aye sir.

We see the same thing in the DS9 episode The Jem'Hadar, where the USS Odyssey tries to draw fire away from two runabouts

O'BRIEN: Half the systems on this ship are disabled. I'm going to have to break formation.
KEOGH [on monitor]: Understood. Return to the wormhole. We'll try to screen you from enemy fire.

The runabouts later return the favor

KEOGH [OC]: Then we're getting out of here.
KIRA: Understood. Dax, let's see if we can take some pressure off the Odyssey.

I doubt the two Miranda-class ships are under orders to run in as cannon fodder and die. But it's entirely plausible they're trying to draw fire from other ships, knowing the risks that entails.

Miranda-class ships were used in other large fleet deployments. The USS Saratoga fought (and was destoryed) in the Battle of Wolf 359. Ships far larger and more powerful were lost that day.