The main reason the Japanese attacked the United States naval base in Pearl Harbor, Hawaii was to discourage American retaliation for Japanese seizure of the Philippines for oil.
The Japanese government, which was heavily dependent on oil imports, was concerned that the United States would cut off its supplies in response to Japan's territorial expansion in Southeast Asia. By attacking Pearl Harbor and crippling the U.S. Pacific Fleet, Japan hoped to deter the United States from entering the war and to secure a quick victory in Southeast Asia without American intervention. The attack on Pearl Harbor was intended as a preventive measure to keep the U.S. Pacific Fleet from interfering with Japan's military actions in Southeast Asia.