Pacific War - Tensions Between Japan and The Western Powers

Tensions Between Japan and The Western Powers

In an effort to discourage Japanese militarism, Western powers including Australia, the United States, Britain, and the Dutch government in exile, which controlled the petroleum-rich Dutch East Indies, stopped selling iron ore, steel and oil to Japan, denying it the raw materials needed to continue its activities in China and French Indochina. In Japan, the government and nationalists viewed these embargos as acts of aggression; imported oil made up about 80% of domestic consumption, without which Japan's economy, let alone its military, would grind to a halt. The Japanese media, influenced by military propagandists, began to refer to the embargoes as the "ABCD ("American-British-Chinese-Dutch") encirclement" or "ABCD line".

Faced with a choice between economic collapse and withdrawal from its recent conquests (with its attendant loss of face), the Japanese Imperial General Headquarters began planning for a war with the western powers in April or May 1941.

The key objective was for the Southern Expeditionary Army Group to seize economic resources under the control of the United Kingdom and the Netherlands, most notably those in Malaya and the Dutch East Indies, known as the "Southern Plan". It was also decided—because of the close relationship between the UK and United States, and the (mistaken) belief the US would inevitably become involved—Japan would also require an "eastern plan".

The eastern plan required

• initial attacks on the US Pacific Fleet at Pearl Harbor, Hawaii, with carrier-based aircraft of the Combined Fleet, and
• following this attack with
  • seizure of the Philippines, and
  • cutting the U.S. lines of communication by seizing Guam and Wake.

The southern plans called for:

• attacking Malaya and Hong Kong, and
• following with attacks against
  • the Bismarck Archipelago,
  • Java, and
  • Sumatra.
• isolating Australia and New Zealand

Following completion of these objectives, the strategy would turn defensive, primarily holding their newly acquired territory while hoping for a negotiated peace.

By November these plans were essentially complete, and were modified only slightly over the next month. Japanese military planners' expectation of success rested on the United Kingdom and the Soviet Union being unable to effectively respond to a Japanese attack because of the threat posed to each by Germany; the Soviet Union was even seen as unlikely to commence hostilities.

The Japanese leadership was aware that a total military victory in a traditional sense against the USA was impossible; the alternative would be negotiating for peace after their initial victories, which would recognize Japanese hegemony in Asia. In fact, the Imperial GHQ noted, should acceptable negotiations be reached with the Americans, the attacks were to be canceled—even if the order to attack had already been given. The Japanese leadership looked to base the conduct of the war against America on the historical experiences of the successful wars against China (1894–95) and Russia (1904–5), in both of which a strong continental power was defeated by reaching limited military objectives, not by total conquest.

They also planned, should the U.S. transfer its Pacific Fleet to the Philippines, to intercept and attack this fleet en route with the Combined Fleet, in keeping with all Japanese Navy prewar planning and doctrine.

Should the United States or Britain attack first, the plans further stipulated the military were to hold their positions and wait for orders from GHQ. The planners noted attacking the Philippines and Malaya still had possibilities of success, even in the worst case of a combined preemptive attack including Soviet forces.