BLUF

The attack on Pearl Harbour by Japan and the declaration of war against the USA by Nazi Germany brought America into WW2; which four years later resulted in the unconditional surrender of both Japan and Germany.

Summary

The Japanese attack on Pearl Harbour was a vicious surprise attack by Japan on the USA base in Hawaii.  Australian wartime Labor Prime Minister John Curtin stated:
'Without any inhibitions of any kind, I make it quite clear that Australia looks to America, free of any pangs as to our traditional links or kinship with the United Kingdom.' This article makes the following points:
  • At the time of the attack, Japan controlled Korea, Taiwan, French Indo-China (Vietnam}, and Chinese Manchuria.
  • Japan aimed to control much of the Asia-Pacific through the Greater East Asia Co-Prosperity Sphere.
  • Although part of the Axis Alliance, Japan was not involved in the war in Europe.
  • Japan's growing empire needed raw materials, particularly oil and pig iron. 
  • America and Europeans in Asia were a threat to Japanese expansion, but the war in Europe was keeping the British Empire occupied, leading Japan to believe that an attack on Pearl Harbour was feasible and strategically necessary.
  • Japan was controlled by its military.   
  • The Japanese naval victories in the 1905  Russo-Japanese war resulted in Japanese military leaders thinking, that like Russia in 1905, the USA would withdraw from the Pacific after the defeat at Pearl Harbour, giving Japan a free hand.
  • The US was not like Russia in 1905, as it was a dynamic and powerful country with strong leadership.
  • The attack aimed to knock the US Pacific Fleet, based in Hawaii, out of the war.
  • Thanks to sightseeing trips over Pearl Harbour, the Japanese had detailed base plans. 
  • By simple observation, they knew the status and location of ships and aircraft.
  • The Philippines and Malaya would be attacked simultaneously as Pearl Harbour.
  • The attack on Pearl Harbour would combine dive bombers, high altitude bombing and torpedo attacks.
  • To stop Japanese torpedoes from running deep in the shallow waters of Pearl Harbour, wooden fins were added.
  • No balloons, blackouts or torpedo nets were deployed at Pearl Harbour, and the US forces did not have any planes in the air.
  • Each part of the attacking Japanese task force had responsibility for specific areas and targets.
  • All US army aircraft were grouped to prevent sabotage.
  • Radar stations were shut down at 0700 hours.
  • The US commanders took some precautions with aircraft carriers rotated in and out of the harbour, ship and naval aircraft patrols and anti-submarine patrols were in operation.
  • After Pearl Harbour, the US agreed to a  Germany first policy with the UK.
  • The Japanese aircraft carriers launched from about 200 miles north of Pearl Harbour when USS Enterprise was about the same distance south.
  • A Hawaiian radio station inadvertently provided a directional locater for Japanese aircraft.
  • Radar operators did detect the incoming Japanese attack, but this was initially dismissed as friendly aircraft.
  • The Japanese used the code word 'Tora Tora Tora' (Tiger Tiger Tiger) to begin the attack.
  • Two waves of aircraft attacked the harbour vessels, and the airfield destroyed two-thirds of the aircraft on the ground.
  • The US Navy destroyed two Japanese submarines.
  • Incredibly Japan did not conduct additional strikes; therefore, the US oil storage facilities remained intact.
Casualties
  • Japan 185 killed.
  • US 2,403 killed.
  • 169 US aircraft lost.
Implications
Learn more about how the Japanese attack on Pearl Harbour unfolded.

References