Japan Miscalculates the Consequences of Starting a War With the US
In 1941, Japan was bogged down in a quagmire of a war in China, with no end in sight. It had recently been hit with American and British economic sanctions, including an asset freeze that crippled its trade. In one of history’s worst decisions, the Japanese government decided to solve those problems by instigating a war with the United States.
The prelude to that decision was American displeasure with Japanese aggression in China, first by seizing Manchuria in 1931, followed by an outright invasion of China in 1937. Back then, America had sentimental ties to China, in addition to economic ones, due to decades of American missionary work, and there was a powerful “China Lobby” in the US. Japan made things worse in 1940 by seizing French-Indochina, which destabilized the entire region. Aside from further proof of Japanese aggression, it brought Japanese forces uncomfortably close to America’s colonial possessions in the Philippines, and British ones in Malaya and Burma.
The US responded by enacting severe sanctions that bit deep. Until Japan withdrew from China and French-Indochina, America imposed an embargo on the sale of products vital to Japan, particularly oil, and froze Japanese assets in the US. The British and Dutch, whose Dutch East Indies (today’s Indonesia) oil fields fueled Japan’s economy, followed suit.
That cost Japan 75% of her overseas trade, and 90% of her oil. The loss of trade was bad enough, but Japan only had enough oil reserves for 3 years of peacetime consumption, or 18 months of wartime consumption. Once the oil reserves ran out, Japan’s economy would simply crash. That presented Japan with a dilemma: bow to the sanctions, or go to war to seize the resources, particularly oil from the Dutch East Indies and rubber from British Malaya, that her economy needed? Pride and the fear of losing face led Japan’s rulers to choose war. They also feared that they would be reduced to an American client state if they caved: what was to stop the US from coercing Japan with sanctions again in the future?
The Japanese hoped for a short war: a few stunning early victories at the outset to bloody the American giant’s nose, and let it know that Japan was serious. They would then seize and establish a defensive perimeter far out into the Pacific and Asia, behind which they would wage a defensive war. Eventually, the Americans, merchants at heart and thus driven by rational cost-benefit calculations would conclude that the war was not worth the effort, and negotiate a settlement. Things did not turn out that way.
To put in perspective the disparity between Japan and the US, we can compare each country’s aircraft carriers during a mostly naval conflict, in which flattops proved decisive. Japan started the war with 10 aircraft carriers. Including what it started with plus what is produced during the war, Japan had 15 large fleet carriers, 5 light carriers, and 5 escort carriers, known as “baby flattops“. The US started the war with 7 carriers. By the time the conflict was over, it had built an additional 160 carriers. They included 24 fleet carriers capable of carrying 90 – 110 planes; 9 light carriers capable of carrying up to 35 planes, and about 125 escort carriers capable of carrying 24 – 30 planes.