You had the first red and gold war after the bothrioc and nyrea were beaten back into the deep tunnels. The out come of said war isn't really stated much but i could assume that it was deadlocked and that both sides agreed to an end of hostilities based around certain terms. The peace lasted for a bit, but wasn't favorable for the federation, hence the aggressive military doctrine, and the attitude that golds are lying, cheating, honey sluts.
The disdain the Federation held and the Lax military regulation of the Gilden republic is what casued the second myrellion war as you can find out from lyralla, you had golds flying patrols, and reds flying patrols both in the same area (borders are real hard to mark in the air without an air traffic control monitoring you on a radar, with a map overlay), not to mention the species is fairly nearsighted, and as steele says 'wouldn't the more eccentric myr be the ones willing to fly?' so you have a pair of eccentric gold pilots who lack discipline flying patrols near their border, while you have highly aggressive, eccentric reds patrolling their border. neither group had ATCs relaying back to them their positions. but the one little skirmish didn't matter against the bigger picture to be honest it's just the spark that set the fire.
the gold queens hated that the reds were more fertile than them, and had a form of government that wasn't libertine and based on fertility. the reds hated the golds for their lack of discipline and structure and their self superiority. in the grand scheme of things a minor border skirmish could have been forgiven, but both sides hated each other so both demand reparations for the others transgression in the border skirmish, both demaned outrageous things that neither would agree to, and that is how the war started.
there is no right or wrong in this conflict, and the only real solution that wouldn't end with either civil war or a continuation of hostilities, would be for the UGC to step in and run the planet until the hostilities and a multiracial government could be established, similar to the un with a single elected official representing the interest of their people. hell you already know who would be on the council, Nezarha, Scalla, Ara Kei, and Taivra (granted this is the best possible outcome as any other red isn't able to separate personal feelings from government, Scalla is the only queen who believes that there can be peace between the two races, Ara Kei is already the voice of the bothrioc but is entirely optional due to their quest, and Taivra is optional as well seeing as you can kill her)
but these are just my thoughts on how the war started and how a middle ground ending could be established