It wouldn't really be a war if it was something that happened quickly.
From how I see the Thargoids behave now versus what we know from the Guardian lore, I'd almost wager to say that these Thargoids aren't the Thargoids from the Guardian era, nor from INRA's fungal genocide a century or so ago.
They seem far too... reserved for that, imho.
If they really were out for genocidal revenge they'd obliterate people in hyperdictions and utterly remove Stations - instead they just scan and leave, or scan and be annoyed until you jettison your (thargoid-)illicit cargo - and just sneeze corrosive ooze on the Stations.
Now; someone mentioned, either on these forums or reddit, that due to the playerbase size involved Frontier cannot really escalate the threat of Thargoids any more then they have in the past without it becoming impossible to handle.
Maybe this new 6-incursion thing will change that...
If that doesn't do the trick of upsetting the playerbase, then Frontier may decide to let that
stolen 300 megaton nuke go off.
On Achenar. Where it may or may not kill the Emperor in the process. Either way is fine.
And then we'll see the Empire, followed by the rest of Humanity collapse into civil war.
And that would reduce the power of Aegis and the Anti-Xeno push, therefor letting the narrative continue in a darker direction by making the Thargoid incursion a nice Xeno-terror clusterfrak.
I did a
"nukemap classic" test on a threehundred megaton Nuke, centered on Utrecht in the Netherlands, and it pretty much takes out all the major population centers in one blast, and lights the rest of the Netherlands, and parts of northern Belgium, on fire. Only a couple of farmers, cows, and communists in the northeast of the Netherlands get to survive - only to get blinded by the blast.
Get your popcorn right now, this is going to get good.