The Rise of Japan
The First World War
American Leadership
Japanese Aggression
Countdown to Attack

Countdown To Attack 1939-1941 

The outbreak of war in Europe in September 1939 was timely for Japan. Deeply committed to a long war of attrition in China, assailed by the Soviet Union in Manchuria and outstripped by American naval rearmament, the success of Japanese expansionism was under threat. However, for the second time in twenty years, the struggle between Britain, France and Germany in a European conflict presented Japan with opportunity. Germany's defeat of France and the Netherlands by mid-1940 left the latter's Far East colonies without protection. Britain, preparing to repulse the Luftwaffe, was also in no position to counter an Asian predator. Politically too, Japan recovered. In June 1940, accommodation was reached with the Soviets in Manchuria and, in September, a tripartite alliance was signed with the like-minded Germany and Italy. By promising mutual assistance to any signatory attacked by a country not already at war in Europe, it gave Japan a perception of security when dealing with the United States. 

However, confrontation with the United States came quickly. In July 1940, America warned Japan not to advance into Indo-China, though the Japanese had already coerced France and Britain into closing supply routes from there and Burma to China. Much more significantly, the US imposed restrictions upon exports of oil and steel to Japan; America supplied 80% of Japan's oil. The deterrent did not work. As the embargo already directly threatened Japan's survival, the Japanese went ahead with landings in Indo-China in September. Positions in the north were consolidated over the winter in preparation for a new offensive in July 1941 to swallow up the rest of the country. 

The conquest of the southern territories would bring the raw materials so vital to Japan. No better opportunity to carry it out would arise as the German invasion of the Soviet Union on 22 June had removed the immediate Soviet threat in Manchuria. Unfortunately for the Japanese, the occupation of the rest of Indo-China hardened the US position. On 25 July, America froze all Japanese assets in the USA and imposed a total oil ban. Britain and the Netherlands followed suit. A decisive moment in Japanese history had arrived. As Japan's oil supplies were now decreasing too rapidly to sustain its territorial expansion, a stark choice presented itself. Either Japan could attempt to restore essential supplies by improving diplomatic relations, which seemed unlikely, or continue its conquests southward and go to war with the United States. 

The precarious oil supply position did not give Japanese diplomats much time. After a period of political infighting, on 6 September the leadership decided that preparations must be made to go to war by early November. Genuine attempts were made by the Japanese to negotiate a settlement, but US demands for a total withdrawal from China and Indo-China were completely unacceptable. After a delay due to a change of Cabinet, on 30 November the Japanese Emperor, Hirohito, gave his assent to the plans for war. The Americans, who had broken the Japanese diplomatic code, were fully aware of these events, but they did not know where Japan would strike. Six days later, Japanese naval and land forces began assaults on Malaya, Hong Kong and the US Pacific Fleet at Pearl Harbor.

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