What you're looking at is Mobile Suit Gundam Thunderbolt: December Sky. This is the movie-length recut compilation of the first four episodes of Thunderbolt, introducing our protagonist and deuteragonist as well as the thoroughly insane environment that was The One Year War and its immediate aftermath. This comes from the Gundam Official YouTube channel, and there is an English dubbed version if you prefer.
The benefit of using a fictional war is that you sidestep all political sensitivities that a real one puts on the table, allowing a storyteller to show an audience what war is really like. The problem is when the creator slips past the boundaries of good taste and narrative discipline to wallow in excess that pollutes the point of the creation (which is, first and foremost, to entertain- no matter the audience). Thunderbolt is not a Superversive story, and it echoes the worst of "Kill 'Em All" Tomino's past exercises in nihilism, but I don't think it goes over that line. Up to it? Sure, more than once, but past? Not yet. It wants to hammer home how tragic this war is for everyone, from those driven psychotically mad to those forced to live with the loss of more than just limbs and everyone in between. Pure Good vs. Evil, as is common for a Gundam series, this is not.
This ain't Unicorn, but neither is it like the downer parts of Zeta Gundam. There is more of this series, but there is no compliation movie of Episodes 5-8 yet, and this film is being made available only until December 8th via the channel so catch it while you can. I guarantee that it's better than watching an NFL game, so make time for it this Sunday.