The Japanese Empire attack on Pearl Harbor, Hawaii, on 7 December 1941, was a crucial moment in the history of the Second World War. Thus, the declaration of war against Japan, voted next day by the United States Congress, was the long awaited act by Great Britain and the USSR, who were no longer alone in the war against Nazi Germany.
Why Japan attacked Pearl Harbor?
The need for raw materials for the economy has led the Japanese ruling elite to choose the way to expansion. In 1931 Japan attacked and occupied Manchuria. In 1937 the Sino-Japanese war begins, which will last until 1945, and in September 1940 the Japanese forces invaded French Indochina.
In response to these aggressions, the US imposed an embargo on (steel scrap metal and aviation gasoline). What was the purpose of this measure? The US sought to stop the expansion of the imperial Japan, by depriving its economy and armies of vital resources and supplies.
Shortly after, Italy and Nazi Germany recognize Japan as the dominant power in the Far East by signing the Tripartite Pact on September 27, 1940. The expansionist policy of the Japanese did not stop there. In July 1941, after another agreement with the French government in Vichy, Japanese troops quickly occupied Southern Indochina.
On July 28, Roosevelt ordered an embargo on all oil sales. Also, all Japanese assets are frozen and Japanese ships were not allowed to enter US ports. The Japanese forces need oil if they hoped to continue the conquests in China. 88% of Japan’s oil imports were from the US.
Roosevelt believed that these economic measures would compel the Japanese to abandon their expansionist plans.
The Japanese knew they had reached an impasse and they didn’t have many options. If they wanted to continue the war against China they knew very well that they needed the vital resources.
Negotiations with the US have not progressed, several times Cordell Hull, Secretary of State, asked the Japanese to withdraw from Indochina and China. For the Japanese withdrawal, meant total humiliation and therefore they could not accept. In an attempt to compensate the US oil, they have tried to negotiate a deal with the Dutch Indies, but the result was not as expected.
Because diplomacy has failed, the Japanese decided it was time to launch the attack to get the vital resources that they could not obtain through negotiations. The Japanese believed that if they could occupy Dutch and British colonies in the Pacific, the issue of vital resources was thus solved.
The Japanese Plan
In the way of the Japanese plans stood the US navy, with the base located at Pearl Harbor,
American fleet at Pearl Harbor was the only force that was able to intervene against the Japanese invasion. As long as the base and American fleet at Pearl Harbor were intact, the Japanese knew that the chances of success of operations in the Pacific were small.
Attacking the base at Pearl Harbor automatically mean war with the US. The Japanese knew that a victory in a long term war against the USA was impossible, because of their immense industrial capacity.
By quickly eliminating the threat represented by the US fleet in the Pacific, the Japanese forces hoped to cause a blow to the morale of the army and the American population. Americans shocked and demoralized after these attacks were then forced to come to the negotiation table.
According to Carl Smith, the surprise attack on Pearl Harbor represented the first step in the Japanese grand plan. The other two phases of the plan were: blitzkrieg for the conquest of Wake Islands, Gilberts, Northern Solomons, New Guinea, Java, Sumatra, Malaya, Burma, Thailand, the Philipines, and Borneo. The last stage was strictly defensive, any forces that invaded the newly conquered territories were to be destroyed. These last two stages were conditioned by the success of the surprise attack on Pearl Harbor.
Japanese forces and the day of the attack
Isoroku Yamamoto, commander-in-chief of the Combined Fleet, was responsible for organizing the attack that would take out of action for six months, the US Pacific Fleet. Although he never wanted war with the US, when the government decided that conflict is inevitable, Yamamoto did not hesitate to dedicate himself to the cause.
Commander-in-chief of the Japanese Combined Fleet began planning the attack since January 1941.
Yamamoto was part of the generation of naval commanders, who believed that air power will represent the future of naval battles.
Isoroku Yamamoto insisted on accelerating the production of aircraft carriers and even opposed to the construction of two battleships. As a consequence, the Japanese air force was to hold the decisive role in the attack on the American naval base.
According to military historian B. H. Liddle Hart, the Japanese naval force consisted of 6 aircraft carriers (Akagi, Kaga, Soryu, Hiryu, Shokaku, and Zuikaku) carrying 423 aircraft, of which 360 were fighter planes. Carriers were protected by an escort group made up of: two battleships, three cruisers, nine destroyers, and three submarines, eight ships were to deal with the supply of this impressive fleet. Also, five pocket submarines were to be used in this attack.
The Japanese naval force stopped at a distance of 275 miles north of the US base. Japanese planes took off from the aircraft carriers between 6:00-7:15 AM. The main targets of Japanese airplanes were: aircraft carriers and battleships. On the day of the attack, unfortunately for the Japanese, no American carrier was in port.
First Japanese wave of the attack reached Peal Harbor on the morning of December 7, at 7:55 AM. The first wave of Japanese attack lasted until 8:25 AM.
The second wave of attack hit the US base at 8:40 and ended at 9:45. During these attacks, the use of torpedo bombers proved to be decisive. In just 90 minutes, the Japanese have dealt a heavy blow to the US Navy. Of the 8 battleships, the Americans lost 4 (Arizona, Oklahoma, West Virginia and California), another 4 were damaged. Three light cruisers and three destroyers were also sunk, four other small vessels suffered significant damage.
Japanese aviation managed to destroy 188 planes and other 63 were badly damaged.
American casualties in human lives amounted to 2403 people and 1178 were wounded. Because the Japanese have achieved the element of surprise, their losses were small: 29 aircraft destroyed, and 5 pocket submarines.
The decision to not organize a third raid against the base at Pearl Harbor and after an expedition to destroy the surviving American aircraft carriers would later cost them dearly. The Japanese have committed another big mistake: because they focused heavily on battleships and aircraft carriers, many facilities at Pearl Harbor as fuel tanks and the submarine base remained intact and later the Americans used them for future operations.
Contrary to expectations, the morale of Americans did not fall after the attack and US were not brought to the negotiations table. Japanese attack managed just the opposite, the American people have united to take revenge for this action.
Until June 1942, the Japanese seemed unstoppable, their armies have seized all operational objectives: Philippines, Malaysia, Burma, Thailand, Singapore, Indonesia, Hong Kong, Guam, and Wake islands American. Meanwhile, US forces have recovered and exactly as the Japanese have estimated at 6 months after Peal Harbor they were ready for the great battle with the Japanese fleet in the Pacific. In June 1942 near Midway Atoll, US showed Japan’s enormous mistake that made through the attack of December 7, 1941. Ironically, the Japanese fleet from Midway was led by Admiral Nagumo, the same who led the attack on Pearl Harbor.
For more information about the balance of forces in the Pacific theater, you can watch the video below: