Because this is impossible. The common economic situation in war is a wartime economic system. The currency is invalid and it is useless if you print it.

Principles of the wartime economic system:

1. All materials are rationed. Everyone has a designated time and place to receive the day's rations. Basically all trade is banned, such as During the Leningrad Defense War, the number of pieces of bread each person could receive per day was fixed;

2. All property can be requisitioned, and "personal property is inviolable" does not apply under the wartime economic system. During World War II, Britain was blocked by Germany and was short of supplies. Even the iron fences in civilian homes were dismantled and melted down to make weapons.

Those people lining up to receive food in war movies existed in actual wars, and those people were not without jobs! On the contrary, these people go to collect food after work!

Therefore, printing money during the war is a pure waste of production capacity. The printed currency is almost no different from toilet paper. After the war, the winners will slowly solve the economic problems, and the losers will be defeated. There is no need to consider economic matters at all.