Except the cultures are almost identical. Same religion, same food, same social norms and customs, same naming conventions, the two languages are mutually intelligible, most Ukrainians also speak Russian, hell even genetically they're almost the same (like I said, east of Galicia and west of Siberia).

I grew up in a Ukrainian-Canadian family, there was no animosity towards Russians whatsoever until the Orange Revolution and the fallout from that... They literally went to the same churches, did all the same things, it was objectively speaking the same culture.