: It's a plot point that can makes sense, but it was presented in just about
: the worst way. Finding peace between the humans and the Elites was the
: most consequential plot point of Halo 2 and Halo 3. While the two sides
: descending into war again can make sense in the right context, hand waving
: huge chunks of the previous games' plot with no explanation is terrible
: writing.

I wouldn't even suggest that a peace between the species was near the most consequential plot point of Halo 2 and 3. Especially given the context of the interactions at very personal and not broad levels for how those ideas are expressed. A few made friends. Most followed orders. Hatred doesn't die easy.

I mean, following WWII the Western and Eastern powers-that-be were not exactly friendly, and while the main authoritative bodies didn't engage in open wars, the number of shadow and proxy wars in the decades that followed are still sewing ramification for us all. You know, like 70 years later and all that.

Halo 4 is 4-5 years after Halo 3? Halo 5 is 8 months after Halo 4.

Disregarding tensions because two main characters saved the galaxy together isn't a logical stretch if you ask me.