Ukraine and Russia just randomly becomes into babies. Probably reborn or IDK- anyways they are still siblings, their mother is a brat but the father is literally suffering right now-

Mother: "Hmm... I think I will name the boy, Russia because it's the strongest country in the world." looks at the girl "And I will name the disgusting trash Ukraine."

Father: "Wow such an amazing mom which totally loves them equally-"

Mother: "SHUT UP-"