Theoretically speaking, World War II was several times more brutal than World War I. The number of militaries mobilized by the countries involved in World War II would only be greater, and the casualties suffered by both the military and civilians would be even more.
Therefore, in the process of preparing for war, Arthur specially instructed the large military factories and industrial sectors to crazily expand production from this moment on, transporting all surplus industrial products and weapons and equipment to the warehouses.
Once the war broke out, there wouldn't be any worry about finding buyers for these stockpiled weapons, equipment, and material resources.
Not only could they be sold to European countries, enabling them to have enough strength to counter the German army, but part of them could also be sold to Asia, creating certain difficulties for the Island nation's expansion at the time.