Mt:6 American participation in World War II

LT4: Explain why the USA decided to drop the Atomic bombs on Japan.

MT:6 AMERICAN

PARTICIPATION IN WORLD WAR II

After Pearl Harbor•On December 7, 1941, two hours after the Japanese attack on American military bases at Pearl Harbor, Hawaii, Japan declared war on the United States and Great Britain, marking America's entry into World War II.•On December 8, 1941 the United States Congress declared war upon the Empire of Japan •The USA has to formulate/prepare a plan for attacking Japan, and Island nation 6,000 miles from the USA

Attacking Japan• Island hopping• Japan was too far away for planes to bomb so the USA decided to capture islands near Japan to use to land planes. • Islands were surrounded by coral and sand bars• Ships would get stuck and

Marines would have to swim to island• Japanese would shoot the

soldiers (2 of 3 died)• Worst island was Tarawa

Strategy

Battle of Iwo Jima• USA needed a closer island

so that they could accurately drop bombs • It was one of the worst

battles• Huge numbers of casualties (deaths) • USA captures Iwo Jima and

begins bombing Japan • Used firebombs-bombs that

exploded then created fires• Kill thousands of Japanese civilians

• Japan showed NO SIGNS of surrendering by April 1, 1945

Decision to drop the Atomic Bomb• Japan was willing to surrender

but they wanted to keep their Emperor• The USA wanted a complete

surrender = no emperor • The USA believed that Japan had

NO plans to surrender • The USA had a secretly been

building a super weapon• Project was called the Manhattan

Project = Creating the Atomic Bomb

• President Roosevelt died prior to the end of the war making VP Truman the president• Truman was advised that using

the atomic would save thousands of USA lives …………..He decided to use it

Atomic Bombs dropped

• B-29 bomber Enola Gay dropped “Little boy” on Hiroshima, Japan• Japan refused to surrender

• Three days later the plutonium “Fat man” bomb was used to bomb Nagasaki. • On August 15, 1945, Japan

officially surrendered, bringing an end to World War II.

Bombing Hiroshima, Japan Bombing Nagasaki, Japan

• The two bombs killed approximately 150,000 people when they were dropped.

• Within a radius of 1 kilometer from ground zero, men and animals died almost instantaneously from the tremendous blast pressure and heat.

• Houses and other structures were smashed, crushed and scattered; and fires broke out.

• Radiation sickness, killed 15 to 20 percent of Japanese after WW2

Questions1. When did the USA declare war on Japan and enter

WW2?2. Describe the strategy of Island Hoping? 3. Why did the USA feel it needed to take over islands in

the pacific ocean?4. Why was the island of Iwo Jima an important victory

for the USA?5. What was the Manhattan plan?6. Which president decided to drop an atomic bomb on

Japan?7. What happened following the dropping of the 2 atomic

bombs on Japan?