Warsaw Pact

USSR: Meet my son, Russia
Yugoslavia: Oh, hello Russia, long time no see. Serbia's in that room if you want to play.
Bulgaria: Hello Russia, long time no see, I forgot to give you this, so here you go (I gave you some energy)
Czechoslovakia: Hello Russia, nice to meet you. Anyway, I saw you when you and your father, the USSR, liberated me from the Nazis. Thank you!
Romania: Hello Russia, in short, although we don’t have family roots, I hope we will always be close to your family!
Poland: Hello, thank you for sending me some ammunition when it was 1944, we were going through some tough times, especially in Warsaw... so thank you for liberating me together with your father.
North Korea: Hello, you're also annoyed by capitalists. I'm really annoyed with their capitalism. By the way, do you have any nuclear weapons?
Hungary: Hello Russia to you and your father, the same thanks, well, for about the same reason as everyone else, thanks for clouding my mind!