Posturing, showing of your military capabilities towards the enemy. Raising morale (aka war propaganda) towards your own population.

Contrary to popular belief, war is mostly about public opinion, not raw strength. Even since (before) roman times, you almost never fight to the last man, you fight until you route the enemy.

I think the word you're looking for is "rout."

military capabilities towards the enemy

...and unfortunately sometimes also military mistakes, but fortunately this doesn't happen often.