Japan wanted a sphere of influence in Asia,and wanted to show
the European powers that had colonies there (British, Dutch, French,
etc)that a new "era" had dawned and that the Asian people were not going
to accept Western rule. That was the most promulgated propaganda used.
The major reason was more economic based as Japan was in great need for
raw materials (as Japan was poor in this area). Japan was especially
lacking in petroleum and SE Asia also provided rubber, rice, and a
market to sell finished goods to.
