As you seem to be coming to this entirely in good faith, I will try to answer as such. Taking into account I am not the Pope of Communism.

that can convince me tankies truly beleive that russian wars and false socialism and authoritarian states are at any level the best possible world.

If you mean the current Russian war, none of us think it is objectively a good thing. We just tend to want the people most affected, the working class and those conscripted to fight in the wars, a peaceful resolution as soon as possible. Fighting to the last Ukrainian would not reach that. We do not think Russia is a great communist savior, at least in its current state.

False socialism, like the nordic model states in northern europe? Yes, I think we agree here.

Authoritarian states. My kneejerk response would be: read “On Authority”, it won’t take you long. Thing is basically a bookmark in length. ProleWiki has it in its entirety I believe.

communism will never come about through the state because no great state or power will ever or has ever willingly destroyed itself.

Are you familiar with the concept of the withering away of the state? The goal isn’t for a state to suddenly “declare Communism” or any form of anti-statist anarchism. During a transitory period of socialism the state would gradually become less necessary. Engels and Lenin both talked about this in depth in some of their more popular writings. One might argue that Stalin-era soviet union really didn’t support this idea, but Stalin himself wrote on the subject. He believed that capitalism would basically not let go without a fight, something we have seen firsthand. Thus he thought a strong socialist state was necessary to prevail against capitalism, before the wither away could occur. Personally, I am very much in agreement with this position.

I am obviously grossly simplifying things, but giving a quick overview that I am sure some of my better read comrades would be happy to elaborate on.