Franklin Roosevelt was president of the US during WWII. While he prepared for war, the US maintained an isolationist policy due to events like WWI and the Great Depression. Japan wanted to conquer Asia and signed a pact with Germany. Tensions rose as the US cut off exports to Japan. On December 7, 1941, Japan launched a surprise attack on the US naval base at Pearl Harbor, destroying many ships and killing over 2,400 Americans. The attack brought the US into WWII but some damage could have been worse if more waves were sent. It cemented support for the war in the US.

1. Pearl Harbor

2. Franklin Delano Roosevelt
• Suffers from polio since 1921
• Former NY senator and governor
• Served under Woodrow Wilson as the
Secretary of the Navy
• Elected in 1932
• Runs for and wins a historic third term as
president in 1940
– The American public did not want a change of
power in the face of a possible threat of war with
Germany

3. American Foreign Policy
• Isolationism
– Adhering to a national policy of non-participation
in alliances, engagements, or conflicts with other
nations
– Roosevelt still prepared the US for war just in
case, even while sticking to isolationism

4. Reasons why US is Isolationist
• Still disturbed by the outcomes of WWI
• Anti-war writings of ex-patriots, veterans
• Concerned with the Great Depression
• New Deal projects (FDR)
• Anti-war films and entertainment
• Peace movement

5. Path to War (1935-1941)
• Neutrality
– Neutrality Act of 1935: Forbids shipment of weapons to
those at war
• Non-Neutrality
– Cash and Carry Act of 1937: Allows sale of non-military
items
– Revised Act: Allows sale of weapons, but must be shipped
in foreign vessels
• Belligerency
– Lend/Lease Act of 1941: Allows US to become weapons
arsenal to democratic nations or those fighting for
democracy

6. USA in 1940
• Not prepared for war
• Experiencing an economic boost due to the
sale of weapons overseas
• Witnessing the balance of power shifting in
Europe
• Congress increases defense budget

7. Japan’s Motivations
• Wants to conquer neighboring China,
Southeast Asia, and establish a “Greater East
Asia Pact”
• Military alliance with Germany and Italy

8. Action vs. Reaction (1940-41)
• Japan: Granted military bases in southern Asia
• USA: Bans shipments of scrap iron to Japan
• Japan: Signs Tri-Partite Pact with Germany and Italy
• USA: Lend/Lease Act approved by Congress
• Japan: Moves into bases in southern Asia
• USA: Freezes Japanese stock assets in America and bans
export of aviation fuel

9. Continued…
• Japan: Proposes summit meeting over pacific
issues and plans for war
• USA: Secretary of State Cordell Hull rejects
summit idea (FDR was at a funeral and could
not attend)
• Japan: Prime Minister Prince Konoye resigns,
Hideki Tojo takes over and orders a surprise
attack on USA base at Pearl Harbor.
Authorized in November of 1941

10. Reluctant Warriors
• Emperor Hirohito constantly asks the Japanese
government to come up with a solution other
than war
• Reads a peace poem at one of their meetings:
– “Across the four seas, all are brothers.
In such a world why do the waves rage, the winds
roar?”

11. Continued…
• Prime Minister Hideki Tojo is convinced war is the
only way. Orders highest ranking commander,
Isoroku Yamamoto, to plan the attack
• Pearl Harbor is decided upon because Tojo thinks
it will crush the American spirit and keep them
from joining the war
• Yamamoto attended college in the US, and knows
their fighting spirit. He plans the attack out of his
sense of duty, but knows it will fail
– Made two predictions that came true

12. The Honorable Yamamoto
• Held out hope until the last moment that
another solution could be found
• Officers thought him cowardly when he told
them they would have to turn back if a peace
agreement was reached after the attack was
planned
– “If anyone will disobey orders and not turn back
when the path for peace is open, resign now!”

14. American
owned
Where is Hawaii?

15. Why is this island so important?

16. • On December 7, 1941, Japanese warplanes
bombed the huge American naval base at
Pearl Harbor in Hawaii. The attack came as a
complete surprise. About 2,400 Americans,
both servicemen and civilians died. Many US
war planes and ships were destroyed or
damaged.

17. Japan’s Pacific Strategy
• Stage 1: Combined fleet attacks on U.S Pacific
Fleet while Southern Asia is seized
• Stage 2: Fortify the chain of islands running
through Wake Island and the Marshalls
• Stage 3: Find, intercept, and destroy any
forces violating their defensive perimeter.
Wage a war of attrition (Total War) with US.
• Key to victory: the American fleet at Pearl
Harbor must be DESTROYED

18. The Operation
• Entire Japanese fleet put on alert to prepare
for battle
• Pearl Harbor assault ordered
• Plan for war, but negotiate for peace
• Submarines must be at Pearl Harbor entrance
to sink exiting ships
• Outcome must be decided in one day

19. Striking Force
• Attack:
– 6 large carriers
– 8 destroyers
– 1light cruiser
– 360 combat planes
• Support:
– 2 battleships
– 2 heavy cruisers
– 3 submarines

21. The Attack
• Yamamoto insists on not attacking until the US
has been given a declaration of war at least a
half hour before the attack
• He is assured they will receive it by his
superiors, and orders the attack
• Sits in silence in his ship’s dining room with
hands folded to await any news

22. U.S Intelligence
• Intercepted a Japanese code:
– “Climb Mount Nitaka 1208”
• Some believe it means an attack is coming on
December 8, while others ignore it
• Receives a warning from Japan in 14 parts through a
telegram but does not decipher it in time
• Japanese planes detected on radar but ignored
because no one was in their office on a Sunday
morning
• Responsible for defense of Pearl Harbor: Gen. Walter C.
Short

24. December 7
• Attack occurred on a Sunday morning, just
after 7 a.m.
• Many men were either still sleep or relaxing
• Men were awoken by the sound of bombs and
explosions
– Taken completely by surprise
• Were able to shoot down some Japanese
planes, but the damage done was
overwhelming

30. Damage
• 4 battleships sunk
3 battleships damaged
1 battleship grounded
2 destroyers sunk
1 other ship sunk
3 cruisers damaged
1 destroyer damaged
3 other ships damaged
188 aircraft destroyed
159aircraft damaged
• 2,402 killed (1,700+ on the USS Arizona)
1,247 wounded

31. The Tragedy of the Arizona

35. Mistakes made by Japanese
• Failure to destroy oil fields on Oahu
• Failure to destroy air craft carriers
• Failure to properly assess damage
• Failure to send a third wave
• Why no third wave?
– Commander Chuichi Nagumo felt that enough damage was
done to the base. Ordered ships to turn back.
– Feared that the US would send a strike force to attack his
ships
– Carriers were needed for another operation in the South
Pacific

37. Shame for Yamamoto
• After the attack ended and he was
congratulated by his officers, he was informed
that the Declaration of War did not arrive until
a half hour after the attack had begun,
meaning the US did not have warning of the
attack. He thought this was very shameful and
dishonorable
• Predicted: “We have awakened a sleeping
tiger.”

38. Pearl Harbor End Results
• US Fleet crippled (not destroyed) for 18
months
• Motivation for US to declare war on Japan
• Unites American people through patriotism to
support a war when they did not want one
originally
• Pearl Harbor is slowly rebuild and refitted and
remains a strategic naval base
• Dolittle Raids were carried out against Tokyo

40. Why was there a surprise?
• US Government thought Japan would attack
Britain before them, since they had ships in South
China Sea
• Attack on Pearl Harbor was thought possible, not
probable
• All messages intercepted did not mention Pearl
Harbor
• FDR was more concerned with Germany than
Japan
• Japanese planning, organization, and skill