Well considering that in many areas English peasants late into the hundred years war had no clue they had been at war with France even after a century, I'm inclined to disagree.
Why? It has yet to be adequately stated why the peasants of Aurvandil would at all care, when they are not in the least bit threatened and when Aurvandil is consecutively winning campaigns, which if anything should provide regional bonuses. Winning battles, taking regions and beating your opponent should make the commons happy, not the other way around. Realms would hold big celebrations when they win after all, the peasants would celebrate etcetera. If war protest coding has negative affects, then it should have positive depending on the context.
Well then their war declaration should have no negative affect, as its relatively meaningless to the commons anyway and won't affect them.
Peasants aren't rational.
They don't know Aurvandil is so much stronger than other realms.
Also, winning shouldn't really matter. Did peasants die in your victorious battle? Yes? Then they're unhappy.
You assume an improbably large amount of nationalistic feeling among peasants.
