Can I still fight for one side or the other after forging the truce in "Season Unending"?
In Skyrim if I haven't done any of the missions to join the imperials or the stormcloaks or signed up for them, can I do so after completing the quest "Season Unending"?
After completing the peace treaty, you will be unable to do any of the civil war quests until you've completed the main quest line.