User blog comment:Wolfishtail/The civil war, which side would a race not native from skyrim or have a ruleing body chose?/@comment-1786741-20120813074703/@comment-80.216.219.47-20120814171225

Redguards would join the Stormcloaks for the chance to exact vengeance on the imperial cowards who betrayed them.

That is really all there is to it.