Why was the US a target of Japanese aggression?

Answer 1

The real reason for Japan's attack (on the US, the British Empire & the Dutch) was the Japanese Army's obsession with their on-going brutal conquest of China. The United States had been taking diplomatic and economic steps against Japan for several years to convince (or force) the Japanese to end their war of conquest in Asia. The Japanese Army actually controlled the Japanese Government since the early 1930's. The Japanese Army refused to end its war of conquest & extreme brutality in China.

Beyond China, the Japanese Army had plans to take advantage of the weakness of the British, French, Dutch & Soviet Union in Asia because of Hitler's conquests in Europe. The Japanese wanted to be free of American interference, and create a vast Asian empire that would have eventually included China, eastern Siberia, Mongolia, Korea, Formosa, Indo-China, Thailand, Burma, Malaysia, Indonesia, Borneo, Sumatra, Java, Philippines, Guam, Wake Island, & New Guinea; and possibly India.

The Japanese military thought that the best way to keep the United States from interfering in their plans in Asia, was to deliver a surprise attack on various US bases throughout the Pacific to do as much damage to the US Military capability in the Pacific. At Pearl Harbor, they intended to sink as many battleships, cruisers & aircraft carriers as possible. At Manila they intended to follow-up with an invasion and capture of the Philippines. At Wake Island they intended to seize the island. The Japanese also attacked the bases, ships & troops of the British Empire. All this was intended to persuade the United States & Britain to negotiate a settlement giving the Japanese most of the western Pacific territories, and most of Asia. They hoped that the US & Britain would not want to fight a prolonged & costly war in Asia to liberate what territory the Japanese could capture in the first six months of the war.

Answer 2

Japan did not target only the United States. Japan had a longstanding war with Russia and China before the US entered WW2. Japan attacked British colonies and possessions including Hong Kong, Malaya and Singapore. They attacked Dutch and French territories also. The attack on Malaya began the day after the attack on Pearl Harbor.