: It was, up to a point. Towards the end of the war, you see the same sort of
: desperate insanity and careless waste of resources that gripped Nazi
: Germany when they were losing the war. The Nazis wasted unspeakable levels
: of capital on wunderwaffe that would change the tide of war, but didn't
: have a snowball's chance in hell of being fielded, or even working. Big
: artillery cannons, inaccurate ballistic missiles, next-generation U-boats,
: even bigger artillery cannons that have to be built into a hill, you get
: the idea.

: So, with the UNSC, you have NOVA bombs that they had no practical way to
: deliver, but instead are forced to target massive Covenant fleets that
: cluster up to make your job easier. You have a new class of child suicide
: troops being trained when augments fit for adults are on the drawing
: board, and you have another supersoldier program where the objective is to
: make augment them to the point where they don't need armor. Maybe they
: have bulletproof, plasma-resistant skin?

: And then the UNSC Infinity took up half of the Navy's budget before the
: UNSC had the technology to make it not die spectacularly in the first
: engagement against a Covenant fleet.

: So, yeah. Impractical, fanciful, but the UNSC needed something that would
: change the tide of the war. Something revolutionary, like how the conical
: bullet and the railroad changed war in the 19th century. But we've gone
: beyond that. This post-war armor, where each Spartan seems to be getting
: an individualized armor type and we have armor that's literally inspired
: by ancient Spartan helmets or samurai, and there's at least three
: different sets for tracking people, is some weird COBRA shit.

Yeah, it's goofy, but as long as they don't take themselves too seriously it doesn't bother me. Halo has always been a bit more light-hearted in some respects, and that ties into it (along with steampunk and pizza skins.) It'll always make more sense to me than the massive number of MJOLNIR Mk V armor variants we got in Reach.

With Infinity, though, I feel like the largely unmentioned implication with the project is that it was being built and designed for a universe where humanity had lost—an Ark rather than a direct weapon of war. As you point out aside from the discovery of the Halos and Trevelyan's engineers it would have missed any sort of major deployment in the war by years, rather than months, and at that point would still have been outclassed and outgunned by the might of the Covenant at its peak rather than the splintered and until only recently impoverished Covenant remnants. At the point it was constructed and until the end of the war, there didn't seem to be any solution to the problem of humanity being stuck on planets that they could not adequately defend. A mobile city solves that, and goes along perfectly to me with ONI's "consider all options" stance.