Answer:
While amongst the World Was at War, the Japenese Army was more on the main focus of concern for fighting against the Soviet Union due to the fact that the army's preoccupation was with Manchuria and China. The Japanese army governed Manchuria indirectly through the "puppet" state of Manchukuo and developed heavy industry there under its favorite agencies, disliking and distrusting the zaibatsu (large Japanese corporations). But the Soviet army's resistance to Japanese attacks was sufficient to discourage northern expansion. In 1937, the intensification of Chinese resistance to the pressure of the Japanese military drew Japan into a draining war in the vast reaches of China proper, and in 1940 into operations in French Indochina, far to the south. Thus, when the navy pressed for a "southern" strategy of attacking Dutch Indonesia to get its oil and British Malaya to control its rubber, the army agreed. While it seems that economic factors were important in Japanese expansion in East Asia, it would be oversight since colonialism, trade protection, and the American embargo compelled Japan to take this course. Domestic politics, ideology and racism took a role as well, but more odf a secendary cause.
Politics
Japan's political structure was inherited from the Meiji era and became increasingly dominated by the military. During the Meiji period, the government was controlled by a small ruling group of elder statesmen who had overthrown the shogun and established the new centralized Japanese state. These men used their position to coordinate the bureaucracy, the military, the parliament, the Imperial Household, and other branches of government. Following their deaths in the early 1920s, no single governmental institution was able to establish full control, until the 1931 Manchurian Incident, when Japan took control of Manchuria. This began a process in which the military behaved autonomously on the Asian mainland and with increasing authority in politics at home. From the time of 1937 on, Japan was at war with China. By the time General Hideki Tôjô became prime minister and the war against the United States began in 1941, the nation was in a state of "total war" and the military and their supporters were able to force their policies on the government and the people. The wartime regime used existing government controls on public opinion, including schools and textbooks, the media, and the police, but Japan continued to have more of an authoritarian government than a totalitarian one like Hitler's Germany. In particular, the government was never able to gain real control of the economy and the great zaibatsu, which were more interested in the economic opportunities provided by the military's policies than in submitting loyally to a patriotic mission.
The emperor throughout historty has been criticized for not taking a more forceful action to restrain his government, especially in light of his own known preference for peace, but Japanese emperors after the Meiji Restoration had "reigned but not ruled." People theorized that a more forceful emperor could have controlled the army and navy at this late date. The doubts are strengthened in light of the difficulty the emperor had in forcing the military to accept surrender after the atomic bombings. The emperor's decision at that point to bring agreement among his advisers was an extraordinary event in Japanese history.
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