The Approach
Attack - First Wave
Attack - Second Wave
The Third Wave Decision
Aftermath

Pearl Harbor: Planning and Preparation 

In early 1941, a feasibility study by Japanese naval aviation experts of the proposed attack on Pearl Harbor concluded that an operation was possible but would be dangerous. It would require the deployment of all six fleet aircraft carriers to be successful. Approximately 400 high-level, dive and torpedo bombers and fighters would be needed. The American carriers would be the primary target. The Japanese made the final decision for war on 6 September 1941, after which detailed planning for the Pearl Harbor attack began. 

Intensive training was undertaken in the shallow waters of Kagoshima Bay, which closely resembled Pearl Harbor. This included the practise of low-level torpedo bombing which was the crux of the whole operation. If it was not going to be successful, declared Admiral Yamamoto, C-in-C of the Combined Fleet, the assault could not go ahead. Only after much difficult experimentation were satisfactory results achieved, a mere three weeks before the attack was due. Also, the delivery of specially manufactured torpedoes to the carriers was not completed until two days before the fleet sailed for Pearl Harbor. 

It was decided that the task force would approach the target on a circuitous route from the north to avoid detection as long as possible by American reconnaissance patrols and merchant shipping. As this would add to the length of the voyage and several ships did not have the range, three refuelling exercises were held in November. The decision also added to the risks, given the likelihood of encountering severe winter weather in the northern Pacific.

Planning was completed by the end of October. All senior commanders were briefed on 2 November and given details of the exercises to be carried out in the coming fortnight. On 7 November, Yamamoto named 8 December (Japan time) as the day of the attack. It would be 7 December in Hawaii, chosen purposefully because it was a Sunday, good weather conditions were forecast and the American fleet usually returned to port in full strength at weekends after training. By 22 November the task force had gathered in Hitokappu Bay in the remote Kuril Islands at the northern tip of Japan. The fleet sailed for Pearl Harbor on 26 November. 

On 17 November, Yamamoto spoke to some key personnel in a farewell address on board the aircraft carrier Akagi. He told the men who were about to embark on this momentous operation that the Americans would be the most formidable opponents in Japanese history. Later, on 1 December during a final conference with the Emperor to endorse the opening of hostilities, the Prime Minister, General Hideki Tojo, remarked that "our Empire stands at the threshold of glory or oblivion".

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