Had an idea. What if an alliances leader can elect to surrender a hopeless situation. By doing this ALL of the remaining flags would be considered to be spent so as to count on their path of valor (if path of valor is active) without having to actually fight a pointless defeat. This could even show up as a stat of wars won by surrender maybe.
I thought about this as my alliance is currently winning a war that the other alliance cannot possibly win as they only have 12 flags left and currently need almost 2,990 points to tie.