Worsening relationship between Japan and the USA

• Japan-US Relations

  • In the 1920s, relationship was good but deteriorated in the 1930s because of the Great Depression and imposition of tariffs by the USA.

  • Tensions increased in 1937 with the invasion of Manchuria.

  • The USA condemned Japan’s actions, provided aid to China and imposed economic sanctions.
• US Economic War on Japan

  • 1937 invasion of China made USA take a harsher line on Japan.

  • President Roosevelt was concerned about Japan’s ambitions.

  • He announced financial and economic sanctions to halt Japan’s aggressive foreign policy.

  • Initials sanctions were ineffective because Japan occupied French Indochina in 1940.

  • An embargo was placed on raw materials such as steel and iron in October 1940.

  • Oil embargo was imposed in August 1941.

  • Roosevelt’s measures would cut off almost 90 per cent of Japan’s oil supplies, crippling Japan’s war efforts in China.
• The Greater East Asia Co-Prosperity Sphere

  • In 1940, Japan launched the Greater East Asia Co-Prosperity Sphere.

  • Aimed at people in various Asian territories that Japan controlled.

  • Goal of ridding Asia of the influence of the United States and Western powers.

  • People of Asia should unite behind Japan to drive foreigners out of Asia.

  • The programme was more for Japan to use the massive resources of its empire in Asia to prepare for war.
• Attack on Pearl Harbour

  • Even with increased output of resources in Manchuria and other territories, J could not challenge USA directly

  • The Japanese commanders targeted the US Pacific Fleet base at Pearl Harbour which protected US and other Western interests in Asia, so they could build its economic base and match USA's power.

  • 7 December 1941, surprise attack launched on Pearl Harbour

  • Attack caused widespread destruction, but did not destroy repair shops, fuel-oil tanks & other crucial naval installations.

  • USA declared war on J, triggering the outbreak of WWII in Asia Pacific.