Maybe we just have different ideas of what constitutes a civil war. I live about 15 miles south of the Mason Dixon line, the border between Maryland and Pennsylvania, which is the fully accepted border between north and south and it is certainly far more historically defined and accepted than what looks to be the borders between what is Russia and what is Ukraine.

Yet even though they were different states in the same federal union, it was considered a civil war.

As opposed to say, the Spanish Civil War, which was more about political factions within the same area.