Manchukuo and World War II.

Japan's occupation of Manchuria was a major factor leading to World War II. Japan was running out of land, had few valuable natural resources, and was politically unstable. These factors, along with many others, led Japan to become more aggressive, in order to take more land, and to be more jealous of the larger powers. This caused many problems, and would eventually lead to World War II. Japan, in the early 1920s to 1930s, was …

…allied, there was bound to be war Japan's aggression did provide new land and resources for Japan, but it also was a source of controversy in Japanese politics. This controversy was what made the army act without the support of the government in the Marco Polo Bridge incident, and it created many enemies for Japan. These enemies forced Japan into an alliance with Germany and Italy, and this set the stage for World War II.