US History - World War II - Japan - Atomic Bomb
Aim: How did the Allies fight back in the Pacific against Japan to victory?
Do Now: Quiz - You have 5 Minutes
Lesson Overview:
| Item | Approx Time |
| Do Now | 3-5 Min |
| Mini Lesson | 15-20 Min |
| Activity | 15 Min |
| Discussion | 5-7 Min |
The Beginning - Pearl Harbor
Most people know that America joined World War II to fight the Germans and Japanese. Fewer people know why or when. America had stayed out of the second World War, which had its beginnings as far back as 1938. However, on December 7, 1941 Japan struck in a sneak attack slaughtering thousands of Americans at Pearl Harbor. But why did Japan attack? The answer: Japan needed oil, in fact they were using almost ten times as much as their small island nation could produce in a year. But just south of Japan is the Phillipines, rich in oil deposits. Thus Japan could thrust outward quickly destroying any meager resistance and taking the oil that they needed. But there was one problem; the Americans. America was rich in resources, natural and human, and was referred to by the Japanese as a "sleeping giant". They knew that America could potentially endanger their plans. To avoid such difficulties a brilliant tactical plan was created by Japanese Admiral Yamamoto and implemented to destroy as much of the United State's Navy at once and potentially remove The United States from its threatening status. America was caught off guard on the Sunday morning in Pearl Harbor and much of its navy was destroyed. But the United States would persevere.
The Philippines
With America crippled Japan continued spearheading outward, invading Thailand, Malaya, Guam, Wake Island, Hong Kong, and the Phillipines. America's gung-ho General MacArthur lead ground troops into Manila to the Bataan Peninsula. His troops were sadly outnumbered and outgunned. This was the site of the Bataan Death March, one of the greatest tradgedies in American History. American ground forces would suffer another devastating defeat at Corregidor, or the Rock, where General Wainwright was forced to surrender as Japanese tanks plowed almost to his front door.
Coral Sea
On the Naval front the United State's Navy faired little better when the planes from the carrier Yorktown and carrier Lexington happened upon two Japanese carriers and managed to destroy one. However, the Lexington was lost as well when the Japanese planes from the remaining carrier retaliated. This was known as the battle at Coral Sea.
Coral Sea (May 7-8, 1942)
Perhaps one of the most haphazard navy battles of World War II, the Battle at Coral Sea was fought with the ships involved never seeing one another. Instead the battle consisted of air raids on the part of either faction. In the end two carriers were sunk, one American and one Japanese. At first, on May 7, the Japanese carrier Shoho accidently encountered flyers from the American's Yorktown and Lexington. The Shoho sank in ten minutes and the lead dive bomber from the Lexington happily radioed back to his ship, " . . . scratch one flattop. . ." However the following day the Japanese fleet shrouded in heavy clouds launched an attack on the Amercians, whom had no such protection. The Lexington took two torpedo hits and two bomb hits, but was left standing throughout the battle. Sadly two internal explosions devastated the ship and Captain Fred Sherman ordered abandon ship. Only one hundred and fifty men were saved. The Yorktown took hits as well, losing sixty six men, but surviving the battle.
Midway
After the haphazard encounter at Coral Sea, America finally got a break that would later become known as the turning point of the war. At the battle for Midway America had a distinct advantage. They had cracked Japanese code, known of the supposed sneak attack and ignored the 'real' attack the Japanese had planned for elsewhere. In this battle America finally established superiority.
Midway June 4-6, 1942)
The decisive naval battle of World War II, turning America's losing fight into a domination over the Japanese Navy. In early June of 1942 , despite Japan's military superiority, America handed the Axis powers a crushing blow in the North Pacific, near Mdiway Island. Although the Japanese did not learn until to late, their planned sneak attack at Midway and been discovered much earlier when America had deciphered the Japanese code.Yamamoto's intentions were to invade Midway Island and the Aleutian chain off Alaska. However these fixed strategies allowed the American forces, headed Chester C. Nimitz, a more flexible attack plan. With such knowledge America had the distinct advantage of suprise, however were still highly outgunned. The Japanese fleet was massive, 200 ships in all, including 8 carriers, 11 battleships, 22 cruisers, 65 destroyers, and 21 submarines. America had three carriers with 233 airplanes and no battleships. But as America struck out swiftly, Japan suffered the loss of one heavy cruiser, four fleet carriers, and 330 aircraft--most of which sat idly on the decks of their respective carriers. America lost only 150 aircraft and one carrier.
The battle unfolded as so: Japan still believed they had a successful sneak attack in progress, and ordered their dive bombers to attack Midway island (an American base). While all the readied aircraft were away at the island, the still undiscovered American fleet launched their attack on the Japanese carriers. Despite the suprise 35 of the 41 launched aircraft were shot down in the first round, but then the second wave hit with no opposition. Three Japanese carriers sank in one hour. For the remainder of the day the Yorktown (US Carrier) and the Hiryu (Japanese carrier) pounded on one another, until both had to be abandoned.
Island Hopping
The term Island Hopping refers not to one single battle, but rather a strategy employed by the Americans as they pushed closer to Japan. The Japanese fortified every island possible between the United States and Japan and fought to the death to hold each island. Taking every island one by one would greatly slow the U.S. forces approach toward Japan and cost untold lives.
Rather than taking out each and every island in between our strongholds and Japan, the United States decided they would invade and decimate an island, skipping one and hitting the next. And while this left a nest of Japanese between American strongholds, the Japanese troops were without incoming supplies and effectively removed from the war. This strategy allow the United States to move across the Pacific more quickly and saved untold lives.
Guadalcanal
Next would come the battle for Guadalcanal, a six month war in and of itself, from which America would eventually emerge victorious. Many smaller conflicts followed, including battles at the Aleutians, Central Pacific, and Philippines.
Guadalcanal (August 7, 1942 - February 4, 1943)
The Battle for Guadalcanal was a smaller war in and of itself. Lasting about six months and filled with smaller conflicts with names of their own Guadalcanal was a costly gamble on the part of the American forces. The tactical plans had been thrown together with little prior intelligence reports, no proper landing rehearsals for the ground troops, no Army reinforcements prepared to back the marine's landing party, the command arrangements were tenuous, and air cover would be problematic. However none of this stopped veteran soldiers such as Colonel LeRoy Hunt (commander of the 5th Marines Division) from telling their troops they expected the operation to be a complete success. And indeed it seemed as much on August 7, when there was no resistance and no casualties to their landings. Fifth and First Division Marines secured the beachhead by late afternoon, however did not reach assigned objectives due to difficult terrain. Coupling the terrain with the hot and extremely humid climate made life hard on all combatants, as well malaria and dengue fever carrying mosquitos were ever present.
By the next day the Marines reached assigned objectives, secured an unfinished Japanese air base, and established a rudimentary defensive perimeter to repel Japanese counter landing. On the same day (the 8th of August) General Rupertus' marines encountered determined Japanese dug into caves and other defensive positions. Americans succeeded in rooting them out by the end of the day. General Vandergrift (command of ground forces on the Guadalcanal campaign) could not have asked for a better start, however his luck did not hold. Rear Admiral Gunichi Mikawa, the Eighth Fleet commander at Rabaul, immediately took action against the invading American forces. Japanese aircraft and naval forces attacked on the 8th of August. After loosing a fifth of its fighters and needing refueling the American carrier withdrew that afternoon. The following day American Amphibious forces withdrew as well. Now lacking air cover and proper equipment to unload cargo sailors were forced to unload only the essentials onto the small beach as best they could. Eventually the supplies were moved into the Marine defensive. After the carrier leaving American forces learned that Japanese naval forces were en route. A warship defensive perimeter was deployed, but failed in the dark of night to spot Admiral Mikawa's five heavy cruisers, two light cruisers, and one destroyer. At 1:36 A.M. August 9, Mikawa opened fire and in the following 32 minutes sunk four heavy cruisers and one destroyer. Perhaps the greatest defeat for American naval forces in a fair fight. Fortunately, Mikawa did not attack the American transports. American naval forces continued to unload troops and supplies until late afternoon on August 9th, then were forced to withdraw. Leaving the Marines short on supplies, and 1,400 less soldiers whom still sat inside a ship. The ground forces were in serious trouble, with only 37 days worth of food and only 4 days worth of ammunition many men began to doubt their own survival.
In such a circumstance, the marines were forced to quickly complete the air base they had captured from the Japanese. By the 18th of August they did so (Naming it Henderson Field, after an air leader who died at Midway) and two days later 31 Marine aircraft arrived. With the air base usable the American force's chances brightened greatly. All the while Vandergrift fortified his base rather than attempt to destroy all the Japanese on the island, however by the 19th sent out reconnaissance teams to scout Koli Point. He did so, in order to verify his fear that Japan was sending reinforcements. At noon of that day the patrol encountered Japanese soldiers, obviously not from the original garrison, that had detailed maps of the American fortifications on Guadalcanal. This indicated a renewed attack on the part of the Japanese. Outraged that they had been prematurely discovered Japan quickly launched a ground force attack, without artillery to back it. At 3:10 A.M. on August 21st Japanese infantry stormed the marine perimeter, penetrated, but were quickly ejected. Ichiki (the Japanese general in charge of ground forces on Guadalcanal) quickly launched a second attack, this time with his naval guns backing his infantry. However the Marines quickly repelled this attack as well. America continued to do well, destroying a Japanese troop convoy on the 24th of August with B-17's and dive bombers.
Unfortunately, these successes merely awakened the Japanese as to the dangers of an American beach head so near their home territory. At that they unleashed attack after attack of ground, air and naval forces. America would continue to take a pounding until September 18th, upon the arrival of 4,612 reinforcement troops, ammunition and additional aircraft. The navy continued to suffer though, as they learned (just as Japan had), it was hard to sail to Guadalcanal. In the reinforcement effort America would lose the Wasp, a heavy carrier.
On October 26th, Rear Admiral Thomas Kinkaid (American) maneuvered two carriers (the Enterprise and the Hornet) to attack Japanese naval forces. In a battle of vicious bombings and kamikazes the Japanese sunk the Hornet and a destroyer, also damaging the Enterprise and a battleship. America succeeded in damaging two Japanese carriers (the Zuiho and the Shokaku) as well as two destroyers. More importantly Kinkaid held the advantage in one specific statistic. He had lost 75 aircraft, while destroying 100 Japanese. It was a loss that the Combined (Japanese) Fleet could not afford. The battle for Guadalcanal was proving costly for both sides, and left both scrounging for forces wherever they could find them.
Iwo Jima & Okinawa
Towards the end of the war America was forcing its way closer and closer to Japan itself, two major obstacles would prove to be Okinawa and Iwo Jima. These bloody invasions and massive loss of ground forces lead to the decision to drop the Atomic Bomb, rather than risk an invasion that would cost countless American lives, as even the women and children of Japan would rather die fighting than surrender to the Americans.
Iwo Jima February 23, 1945 to March 26, 1945)
Iwo Jima is a small volcanic island, a mere 700 miles from Tokyo. Its location made the taking of it crucial to the United State's further plans in the war. It would come at a cost. For three days straight the island was relentlessly pounded by battleships, cruisers and planes from the aircraft carrier. When America thought it safe ground troops were sent in, however 3,000 casualties resulted in the first day. The island of Iwo Jima is honeycombed with caves and concrete pill boxes, so much so that the prior bombardment had done little to the 20,000 Japanese defenders.
The job of the invasion was that of General Harry Schmidt, and the Fourth and Fifth Marine Divisions. Within four hellish days of fighting the marines had pushed to the top of Mount Suribachi. Here they raised the United States flag, and photographer Joe Rosenberg would take the snap shot that would become one of the most famous images to ever come out of World War II.
Despite this inspirational moment the fighting was far from over. The marines continued fighting the dug-in Japanese soldiers from hole to hole and cave to cave. Soon U.S. soldiers were issued satchel charges filled with dynamite and napalm to force the Japanese out of their holes. By the time the Americans had successfully captured the island only 200 fanatic Japanese soldiers were taken prisoner. The rest had preferred death before defeat.
- American Losses at Iwo Jima:
- Estimated loss of 33% of landing party
- Deaths = 5,885
- Casualties = 17,272
Okinawa (April 1, 1945 to June 22, 1945)
The beautiful island of Okinawa was the next step for United State's forces, because its capture would leave Formosa (Taiwan) isolated. It would also put America within striking distance to deploy troops and air raids to main land Japan. Unfortunately for the landing ground troops, the commanding officers had underestimated the defending forces. Oddly enough though the defenders did not decimate the Americans as they unloaded onto the beach, in fact they never truly attacked. As the United State's troops moved onward they met very little resistance until the April 7, 1945. On this day they had found the defensive perimeter, the Machinato Line, and it took six days to fight past it.
All the while Japan had organized massive air sorties from the surrounding fleets. Hundreds of suicidal kamikaze attacks rained down on the U.S. Navy. About 5,000 sailors died and many ships were damaged.
Meanwhile on the island the marines encountered Shuri Line, the next line of defense. American casualties mounted, but mostly battle fatigue rather than physical damage. In time the marines caused Shuri line to collapse and met up with the last ditch Japanese soldiers. But as defeat became imminent Japanese soldiers began throwing themselves off the cliffs that surrounded the island. The Americans suffered 50,000 casualties. The Japanese on the other hand had began the battle with 117,000 soldiers and ended with only 7,000 still breathing.
The Development of the Bombs
When the idea of these bombs were first being developed it was planned that each atomic bomb would be the equivalent of 2,000 B-29's with there maximum load of 10,000 pounds of bombs. The first atomic bomb tested at Trinity on July 16, 1945 proved that the U.S. was in possession of the most destructive weapon ever devised by man. The bomb was powered by the splitting of all the nuclei in several kilograms of plutonium. A sphere of plutonium the size of a baseball produced an explosion equal to 15,000 to 20,000 tons of TNT. When the bomb exploded at Trinity at 5:30 a.m., it vaporized the tower and turned asphalt around the base of the tower to green sand. Suddenly the sky was brighter than several suns. Seconds after the explosion came a huge blast that sent withering heat across the desert.
A massive orange and yellow cloud in the shape of a mushroom surged and billowed upward reaching into the sub-stratosphere up to an elevation of 41,000 feet. A soldier 10,000 feet away was knocked off his feet by the force of the shock wave. The flash of light was seen more than ten miles away, and a soldier five miles away was temporarily blinded. The explosion was heard 50 miles away.
Uranium Bomb: Little Boy
The uranium bomb detonated over Hiroshima was a fairly simple design, as far as nuclear weapons are concerned. It was also relatively low yield for a nuclear device. It was designed with two pieces of uranium, one in the shape of a large cup, the second a cylindrical slug, when the two pieces were brought together they would reach critical mass and create a chain reaction. The cylindrical slug would be fired into the 'cup' through a gun barrel and yield 20,000 tons of dynamite worth of explosives. The scientists which built Little Boy were so confident it would work they did not even test the method prior to Hiroshima.
Plutonium Bomb: Fat Man
This type of bomb could potentially yield more explosive power with less material, the only problem was that the 'gun' method used in Uranium would cause plutonium to detonate prematurely. Thus an implosion trigger was created. What this did, was take a ball of plutonium, not quite to critical mass, then surround it with synchronous explosives that would cause the ball to implode and reach critical mass.
Hiroshima (August 6, 1945) and Nagasaki (August 9, 1945)
In late May 1945, a committee of military officers and Manhattan Project scientists chose Kokura Arsenal, Hiroshima, Niigata and Kyoto as potential targets for the atomic bombs. They believed that attacks on these cities, none of which had been bombed before, would have a profound psychological effect on the Japanese. Kyoto was later removed from the list because of its cultural and historical significance, and Nagasaki was added in its place.
With the capture of Iwo Jima and Okinawa, the distance from US troops and Japan closed greatly. Thousands of lives were lost in the occupation of Iwo Jima and Okinawa. President Truman feared that an invasion on Japan would cost thousands more lives. This fear sparked the decision to drop the Atomic Bomb. The first bomb was dropped on Hiroshima. Hiroshima was hit first because it held no American POW's and was an important communications center for the Japanese military. The B-29 Superfortress dubbed "Enola Gay" after the pilot's mother, was the first plane to drop the Atomic bomb. Pilot Col. Paul Tibbets brought the plane up to an altitude of 31,000 feet then released "Little Boy". The Enola Gaybanked sharply and accelerated, getting 11.5 miles away from the site before the bomb exploded.
The immediate vacinity around the bomb was vaporized. Everything within a 4.4 square mile area around the detonation was burned. Out of the 300,000 inhabitants of Hiroshima over 100,000 people were killed, with about 70,000 or more wounded. The Japanese refused to surrender. A second Atomic bomb was dropped on the city of Nagasaki, by Major Charles Sweeney in his B-29 "Bockscar". However Nagasaki was no the intended target, Sweeney was meant to take out the Kokura Arsenal. First a fuel pump went out, and then Kokura was obscured by clouds, thus Sweeney moved to the secondary target. Nagasaki was home to Mitsubishi Stell and Arms Works. It too, was covered in clouds, but then for one moment the clouds opened up and "Fat Man" could be dropped. 40,000 people were killed and around 40,000 injured from the blast.
Japan Finally Surrenders (September 2, 1945)
Although the surrender was an unconditional one signed on the United States battleship Missouri there was still conflict in Japan as to if they should surrender. After the bomb on Hiroshima, President Truman of America, warned that another such bomb would be dropped if Japan did not surrender within 24 hours. The Japanese Council of six was split three to three as to surrender or continue the war effort. After the second bomb things change and the war council was replaced by a new Cabinet, which went to the Emperor and persuaded him to call an imperial conference. At this conference the Emperor emotionally gave his opinion that Japan should surrender to the United States. Thus on September 2, 1945 to Japanese officials in full formal wear and top hats strode on to the deck of the battle ship Missouri and signed the unconditional surrender. The Allied powers were represented by General Douglas MacArthur, who said, "when everywhere can walk upright in the sunlight.", referring to the new era of peace. Afterwards MacArthur would personally take control of Japan and rebuild it with American backing.
Classwork & Homework
Lesson PowerPoint: World War II - The Pacific Theater
Lesson Activity: Atomic Bomb Decision
Homework: Complete Lesson Activity