Perpetual astartes and the imperiums response to positive interactions with Xenos.

No idea what a perpetual astartes is, but the Imperium has lots of contact with probably hundreds of thousands of xenos. They even do trade with them. These are all xenos that occupy maybe 1 planet, a solar system or maybe a modest little seller empire. Most are primitive, peaceful, unambiguous or live on planets Imperials don't want or some other combination. So long as they are not a threat and don't compete for resources, the Imperium leaves them alone, ignores them, or passively exploits them through trade.

Despite all the anti-xenos rhetoric, the Imperium peacefully interacts with a lot of Xenos. They have way bigger threats and better uses of resources than exterminating some hapless lizard people on Planet X, which is toxic and uninhabitable anyways.

/r/40kLore Thread