December 7th - the date that has lived in infamy - each year marks an anniversary of the Japanese attack on Pearl Harbor. It was this act of aggression that effectively brought the United States into World War II.
But what was the international geo-political situation that led to this blatant show of force? Japan was a much smaller nation with limited military resources; they seemingly could ill-afford a direct conflict with the United States, yet they chose to attack anyway. But why?
Japanese leadership argued a method to their madness. The presence of a United States naval base so close to mainland Japan in particular (and Southeast Asia in general) represented a potential threat to planned operations against the overseas territories of nations with which Japan, as an ally of Hitler’s Germany, was already at war.
The Pearl Harbor attack was arguably the ultimate result of two decades of planning. Relations between Japan and the United States had been tenuous since the 1920s. While continuing the mutually beneficial relationship of commercial trade partners, tensions escalated in 1931 with Japan’s invasion of Manchuria. Throughout the ten years prior to the Pearl Harbor attack, Japan had aggressively expanded into China and subsequently engaged in the Second Sino-Japanese War in 1937 in trying to completely overtake China and its resources.
From December 1937 onward, Japan demonstrated gradually increasing degrees of an aggressive stance against the United States. Several unsavory events (e.g., the USS Panay was attacked; the “Allison Incident” occurred; the Nanking Massacre; etc.) all served to swing American public opinion decidedly against the Japanese. Subsequently, the United States escalated its assistance to China directly with loans and war supply contracts. These acts in turn infuriated Tojo and Japanese military leadership.
Regardless, the “friendly” commercial relations with Japan had continued on a civilian level. While America may not have favored Japanese actions against China and other Asian areas, a state of contractual agreement was still technically in effect, thereby essentially forcing the United States to ensure delivery of goods in accordance with existent contracts. Thus, the United States had maintained steady shipments of goods to the Japanese, despite growing discontent of the American public and political officials.
This amicable business relationship soon ended. In an attempt to stop the flow of foreign supplies into China, the Japanese invaded French Indochina in 1940. This event was deemed to represent just cause to render existent contracts null and void, and the United States immediately ceased shipments of airplanes, tools, and other supplies to Japan.
However, exports of oil and gas continued. Due to the dependence of the Japanese on the supply of United States oil products, it was clear that the cessation of these essential necessities would be perceived as an act of war by the Japanese government; Roosevelt was not yet ready for such a conflict.
Although contractual relations with Japan were being maintained, FDR continued to prepare for the possibility of war. He moved the Pacific Fleet out from San Diego to Pearl Harbor in mid-1940. He also bolstered the US military presence in the Philippines.
But it was the cessation of US oil exports to Japan that, to the Japanese, was the proverbial last straw. Subsequent to Japan’s completed takeover of French Indochina, and partly due to a shortage of domestic oil in the United States itself, FDR ordered an end to exports of gasoline and oil to Japan in July of 1941. The Japanese were immediately faced with a problem. The need for oil and gas led them to focus on a takeover of the oil-rich Dutch East Indies, an act which Roosevelt warned would be considered an act of war.
Negotiations then ensued between the two nations. Japan sent an envoy to Washington and offered to withdraw from most of China and Indochina in return for a continuation of oil and gas trade. This proposal was rejected by FDR. Japan then requested a meeting between Roosevelt and Japanese Prime Minister Konoye, but FDR insisted on reaching a working agreement prior to any meeting. Meanwhile, open conflict between the Japanese military leaders and the Konoye administration further hindered any progress in diplomatic resolution. A final proposal was tendered on November 20th, and a counter-offer (the “Hull note”) as returned by the United States a week later, but by then it was too late to preclude war.
It was the cumulative effect of these political and military maneuvers and personal perceptions (some accurate, some not) on both sides that led the Japanese and the US to come to view each other as enemies simply waiting the spark to ignite open warfare. Ultimately convinced of America’s support of the United Kingdom and its allies, regardless of any agreements to the contrary, the Japanese military leaders were already preparing for what they deemed to be the inevitable: a task force sailed for Pearl Harbor on November 26, the day before the Hull note was delivered to Tokyo.
And the rest is history …
