It might be a way of working up anger, it might be a way of scaring the enemy so that the fight never occurs and nobody has to die.

According to an anthropology course I took long ago, people tried to avoid actual battle in previous times, perhaps by scaring the enemy away with war cries, war paint and bagpipes or perhaps by having champions (think David and Goliath) fight on behalf of both sides.

Would that we could return to such eras!

I might even tolerate uillean pipes in such a noble cause.