War economies are economies that are focused on preparing for and fighting wars. They can involve changing taxes and laws to raise money for war, making more factories to produce weapons and supplies that are needed in battle, and also changing the way people live their lives. For example, people might have to start using certain materials they wouldn't usually use because of how scarce resources can be when a country is at war. When a country goes to war, it needs a lot of resources and money to be successful in the fight. The war economy is the economy that takes care of this need.