As seen in WW1 trench warfare was out of date because weapons could fire quickly and more efficiently, therefore being more deadly. The use of planes to bomb enemy factories really changed war because they could defeat an enemy through attrition (not having enough supplies to support the army.) the birth of battlefield telephones made communication with the front lines easier. Through communication, men on the front lines could call for backup to be sent to them from a base. Tanks were faster and more reliable, for example the German blitzing. Tanks could move very quickly and overcome the enemy, and they were very destructive.
Changes like these made battles sometimes very quick and mostly urban, as machine guns came into play.
Since the BOP essentially serves as the financial ledger and source of truth around a country's financial transactions on all fronts, you can imagine that it is incredibly important. The BOP can reveal the economic health of a nation and help economists postulate its future economic landscape.
