I am a huge Warhammer 40k fan and I once met someone who was also a 40k fan. Dude said he played Imperium cause he was (and he said this with zero irony) a “human supremacist.” Genuinely though the Imperium were good guys. I feel like it’s needless to say, but I stopped talking to him.
The closest thing an anarchist would ever advocate for in regards to an internal peacekeeping force would be some sort of community defense to defend against violent threats to community. But there would be ways to prevent it from becoming centralized and abusive. One way is by training everyone in the community in community defense and rotating the role. Their are other ways as well. But besides the point