To explain their empire and concur more land
The columbian exchange had a very negative effect on the Native Americans. The native americans received mostly disease from Europeans, but also certain plants and animals. Syphilis is one thing Europeans contracted from Native Americans.
Poor growing conditions, droughts, disease, Native Americans, less profit because it costed more to transport crops.
The conditions were different because germany had to pay millions of dollars due to the treaty of Versailles.Japan was different because they signed an alliance with Great Britain after WW1