system
Given the following post, respond as if you're commenting on Reddit:
human
[40k] are there human vs human conflicts still?

So I know humanity is mostly under the imperium. And I know there is chaos space marines.

But given all the planets in the universe. Are there wars between human vs humans. Like imperial guard vs some other military, or two human  militaries battling it out in a civil war unrelated to the imperium?

I'm still new to the 40k lore, so forgive my newbie questions.
gpt
Despite the Divine Light of the Emperor shining across the Imperium, there are of course those who struggle and fight against their fellow man. Civil wars for control of a local planetary government are fairly common across the Imperium, but these are largely ignored by the Imperium at large unless the tithe is interrupted, heresy and Chaos are spreading, or more planets are dragged into the conflict. As well, the majority of Chaos forces consist of human cultists, who will often attempt to take over a planet in the name of the Ruinous Powers. In these cases, the Imperium will often send Imperial Guard units to fight the traitors and reclaim any lost territory for the glory of the Emperor.