The Invisible Observers are responsible for mantaining and regulating the metro's population. And in 2035 we find out that, Red Line, Polis, Hanza, Reich are all the same thing just different cover, they are all factions of the Invisible Observers. On the wiki here, the Rangers are not listed as a faction of them but in the book we here Miller reporting to Bessolov. So, if everyone is controlled by them, does that mean that the Red Line-Rangers war over D6 was known by Miller? Did he know that he will sacrifice most of his team? Or was he just a victim like the other rangers and didnt knew about the attack. In the book, Artyom accuses him of selling out all of their guys to Besolov like a pussy. And we see Miller having PTSD drinking with the dead Rangers on the wall in his office, so I think he knew about the attack, and he had orders from Besolov to carry the war without exposing the Invisible Watchers so that way everything was just an act. He acted like the Reds really attacked them, poor rangers. I am really confused. So in conclusion:
Was he under control of Besolov at the time of Metro Last Light?
Did he know about the attack and knew it is all show and planned?
Was it even all show and planned? Maybe, the RedLine acted without caring about Besolov.