What I'm confused about is *how* the Elders are compromised by the Vishnans, and why the Vishnans are acting the way they are...it just doesn't add up as I understand it.
They extensively manipulate and help shape human culture/society in Sol for decades, resulting in Ubuntu and the UEF. Come WiH, the UEF is invaded without provocation (justified or not) by an outside, unforeseeable force, which they resist for 20-ish months with purely defensive tactics while they struggle to defend themselves and reconcile this war of self-defense with their nature of Ubuntu and diplomacy. They're still holding on fairly well, and apparently there is hope for a victory that is not won purely through force of arms.
So the Vishnans do a 180 and not only completely give up on humanity as a whole, but order a xenocide of humanity? Dafuq? And it's implied that they did this roughly a year ago--long before Jupiter fell or Ubuntu was truly in jeopardy. So...seriously, what the **** is up with the Vishnans? Aren't they just making themselves look like childish, foolish, and inferior counterparts to the Shivans almost immediately after they berated the Shivans for being 'clearly' wrong about humanity and the Vishnan plans for them?
For a nigh-immortal race, the Vishnans sure have ridiculously little patience or tolerance, not to mention determination to try harder or see things through. The moment their own plan doesn't go perfectly, they abandon the plan and order a purge of all of its elements?
In this sense, it wasn't the Sol War that triggered the Vishnans' abandonment of humanity, or the growing interest of the Shivans. It was their own utter failure to plan or adapt that caused it, on top of the fact that it takes *so little* for them to abandon humanity in the first place.
But further, both the Vishnan and Shivan positions about judging races seems ludicrously absurd. It's like butchering all toddlers who aren't exceptionally mature, rather than giving them a chance to grow, learn, and develop before deciding whether to spare or massacre them. So the Vasudans and Terrans had a fairly low-intensity war shortly after first contact? Okay, but at least they seem to be learning from the experience and--notably--are not trying to enslave or exterminate each other. So mercilessly wiping out both races is somehow a more 'mature' course of action? What the hell? It's not like they're protecting any other races, either, as there were no others under threat.
As for the potential Nagari network problem, wouldn't it be both more ethical and productive to guide and enlist aid from races to help secure the Nagari network and counteract the Great Darkness, rather than exterminating every race that makes it to a vague, eventual technological point, without warning or compromise?
The GTVA is rightfully paranoid about the Shivans and Vishnans, but the problem is that they shouldn't *have to be* in the first place. They're not dealing with Cthulhu here, they're dealing with two all-powerful races that routinely commit xenocide on a whim because they can, even when they are directly at fault for any perceived offense. Yeah, enlightenment and pacifism is kind of hard to achieve in the face of unknowable, unstoppable, constant xenocidal aggression that doesn't even try to reach any kind of understanding with you.
Were it not for stupidly hypocritical Vishnans and omnicidal maniac Shivans, the GTVA and UEF could find a peaceful solution (or could have) quite feasibly. Unfortunately, something called The Great Darkness might give a slight justification for the Shivans and Vishnans treating other races at all like they do and for them being anything more than complete, despicable monsters that are infinitely worse than the Ancients ever were.