Japan's attack on pearl harbor was motivated by its need for raw materials, including

 Oil. 
Japan wanted southern Indochina's supply of oil as they were starved for it and unable to maintain their military. On the same day they attacked Pearl Harbour they also attacked the Philippines to gain access to this oil. The attack on Pearl Harbour was to prevent any armada of US ships from retaking the Philippines, which they succeeded at doing. 

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Japan's attack on Pearl Harbor was motivated by its need for raw materials, including oil. Hope this helps.

Herodotus taught that absolute right and wrong did exist.