Not only did they obviously want more territory, but the islands they conquered were rich in Natural Resources. More money, more land, more power.
Japan was at war in Asia, Germany was at war in Europe. Both of those countries were engaged in territorial conquests.
China during the 1930's, the rest of the conquests occurred in 1941 & 1942.
Conquests.
not advanced at all. Before WWI Japan was very isolated from the other countries and had almost no modern technology. After being exposed to other more advanced countries they rapidly advanced
Japan had conflicts with China and Russia before World War one.
Hideki Tojo, the Prime Minister of Japan during much of World War II, oversaw Japan's military expansion, but he did not personally conquer countries. Under his leadership, Japan invaded and occupied several territories, including parts of China, Korea, the Philippines, and numerous Southeast Asian nations. The extent of Japanese conquests varied, but by 1942, Japan had significant control over much of East Asia and the Pacific. However, these conquests were part of a broader military effort rather than the actions of Tojo alone.
To keep the US from interferring with their other conquests.
Germany, Japan & Italy signed a "Tripartite Pact." Once they began their conquests upon other countries, the remaining UN-Conquered countries formed their own alliances to fight back.
The Netherlands and Portugal.
As Japan grew strong it began making imperialistic moves toward other countries. It also strengthened its military and gained control of its trade tariffs.
The Philippines had trade relations with such countries as China, Japan, Thailand, Malaysia and Indonesia.
Because it would invole more countries making another war making chaos and so on