Sure it was a civil war, but it had few of the ill effects of a normal civil war.(i.e. no one was taken over, so there was only hard feelings between factions, rather than oppressor and oppressed).
Some might consider the loss of thousands of soldiers and civilians, the creation of thousands of widows and orphans, total destruction of homes and livestock and incalculable damage to the economy "ill effects" consistent with any war, civil included. And that's just in Ostermark, not to mention the other three provinces.
War:
The only way to win, is not to play.
The only way to play, is with toy soldiers.