I'm curious as how others look at this scenario. While I don't anticipate it really happening on the PC level (aside for Starfinder equivalent of Kingdom Building...whatever that would look like), I'm wondering what the general narrative rules would be so I could do some world building.
From what we know via books, before the Zerg/Tyranids/Swarm showed up, the pact and the Vesk were doing their own Imperialism runs to acquire resources and build more pylons for their fight vs each other.
Pact law in general says, "unless you're a protectorate of ours, we're basically hands off". Snippets of narrative of the station talk about explorers fighting each other in the politco-government deck to put in their claims on new worlds and stuff in before each other.
But what would be reasonable rules?
If you can take it and hold it, its yours?
Explorer Betsy can claim an entire star system because she found it?
Explorer Betsy can't really claim a star system but if she's done enough recon, she can stake a claim on its data and sell that stuff for phat lewt?
I file a claim for Earth of behalf of Supermegacorp and we start colonizing it, but Ultramegaincorporated decides to jump our claim on the other side of the planet?
I kinda feel its a combination of first come first served mixed with 'only if you can hold it'.
Which potentially means if you're an independent mining group on a backwater planet that suddenly finds itself between 2 megacorps, you could end badly.
Maybe some scenario of "If you're a Pact Worlder, and want to continue to benefit from protection of Pact World stuff, you have to follow a set of rules when it comes to claiming stuff'
kinda like how in real life we've got sorta international agreements on space and solar-system resources ownership....even if we can't really use any of those solar-system resources yet.
I like the idea of setting things up as a "claim" system akin to the American and Austrialian settlers, but with a bit of a twist.
I'm sure the Pact Worlds have an overworked and underfunded department keeping track of claims to survey areas and various worlds. They also have a different department keeping track of inhabited worlds and stellar nations for diplomatic purposes. Nefarious corporations or people may try to claim ownership of planets regardless of indigenous populations as surveyed and staking claims. Starry-eyed Starfinders may try to get their new finds recognized as independent nations.
For all of them, of course, possession remains 9/10ths of the law. That creates a chaotic enough system that PCs can't claim and keep huge swathes of territory easily, but does allow enterprising and tenacious PCs to form their own (micro)nations.