April 5, 2010
Each of us spin-masters can make a case of the start of WW2 in the Pacific. If the first shell fell on Kota Bharu 85 minutes before the first bomb fell on Ford Island, it was while 185 strike aircraft from four aircraft carriers were en-route on the 1-1/2 hour flight to Pearl Harbor and while five miniature submarines were trying to (one, maybe two, succeeded) in entering the inner harbor, an act of war.
Similarly, because USS Ward (DD-139) fired on and sank a mini-sub over an hour before the bomb fell on Ford Island, a spin-master might say that the USA fired the first shot and started the war with Japan. ;^)
The more significant point is that the order to expand their war with China was given by the Emperor several days before these events. That decision sent two ready Japanese fleets, one east, one west, and several ready task forces, to start an attack at 1800 Zulu/GMT/UTC, 7Dec1941.
This was just a phase of their purpose of conquering China and they needed the resources of oil, rubber, and tin from the Dutch East Indies. Holland and Britain were tied down by a war in Europe and were in no condition of stand in the way of Japanese ambitions. Because Japan had signed a military pact with the Axis enemies in Europe, the ABD powers would not supply war materials to their enemies.
The reason Japan attacked Malaya was 1) to shut down the supply line to China through Burma, and 2) to protect their flank when they attacked the East Indies for the resources they needed to pursue the conquest of China. In their strategic planning, the Japanese felt a need to occupy the Philippines which sat on the supply-line between the Dutch Islands and the Homeland. The Philippiens were an American territory, therefore the Japanese planners saw a need to protect their back by eliminating the US military at Pearl This brings into strong light why the attack on Pearl was so casual and was not pressed with vigor -- there was not intent of conquest, just swat the Americans to keep them away from the real task of taking Dutch oil. The did not seek war with the USA, but rather to discourage the US from warring with Japan.
The mistake the Japanese planners made was to assume the US would not make a big deal out of losing the Philippines, because to respond to Japan would have activated a much more serious response from their treaty partners, the victorious German-Italian Axis. The British and Dutch were already engaged in a losing a war in Europe. Even Japan's traditional enemy, Russia, was being defeated. Surely the US would not be so foolish as to enter into a war they were certain to lose, too.
All of the goals of the Japanese strategy were accomplished in short order -- the supply line from India was cut ; the oil, rubber and tin were acquired from the East Indies ; a defensive perimeter was established along the international dateline on the Pacific side ; and the British were pushed out of the Indian Ocean to Africa opening a potential Japanese tie to the Axis in the Middle East. However, the US put up with that 6-months of defeat ; Adm Fletcher/Nimitz held the line while America mobilized her people and industry -- and the rest is history.