What caused the atomic bomb on Hiroshima and Nagasaki?

Answer 1

Because an invasion of the Japanese mainland would have been hugely expensive in terms of US Military lives, given the experiences of recapturing Islands & Island Groups taken by the Japanese, the use of Atomic power in the dreadful destruction of 2 cities brought about the end of Japan as a belligerant power. Also it was imponderable just how long it might have taken to bring about the end of the Pacific War by conventional means.
On August 6, 1945, at 9:15 AM Tokyo time, a B-29 plane, the "Enola Gay" piloted by Paul W. Tibbets, dropped a uranium atomic bomb, code named "Little Boy" on Hiroshima, Japan's seventh largest city. In minutes, half of the city vanished. According to U.S. estimates, 60,000 to 70,000 people were killed or missing, 140,000 were injuried many more were made homeless as a result of the bomb. Deadly radiation reached over 100,000. In the blast, thousands died instantly.

The city was unbelievably devastated. Of its 90,000 buildings, over 60,000 were demolished. Another bomb was assembled at Tinian Island on August 6. On August 8, Field Order No.17 issued from the 20th Air Force Headquarters on Guam called for its use the following day on either Kokura, the primary target, or Nagasaki, the secondary target. Three days after Hiroshima, the B-29 bomber, "Bockscar" piloted by Sweeney, reached the sky over Kokura on the morning of August 9 but abandoned the primary target because of smoke cover and changed course for Nagasaki.

Nagasaki was an industrialized city with a natural harbor in Western Kuushu, Japan. At 11:02 a.m., this bomb, known as the "Fat Man" bomb, exploded over the north factory district at 1,800 feet above the city to achieve maximum blast effect. Buildings collapsed. Electrical systems were shorted. A wave of secondary fires resulted, adding to their Holocaust.

Flash burns from primary heat waves caused most of the casualties to inhabitants. Others were burned when their homes burst into flame. Flying debris caused many injuries. A fire storm of winds followed the blast at Hiroshima as air was drawn back to the center of the burning area. Trees were uprooted. The bomb took the lives of 42,000 persons and injured 40,000 more. It destroyed 39 percent of all the buildings standing in Nagasaki. According to U.S. estimates, 40,000 people were killed or never found as a result of the second bomb.

Answer 2

Since August 1945 there has been debate about whether or not the use of nuclear weapons in Japan was necessary and/or advisable, a debate which still continues. This answer will not address that debate. Some reasons for the Hiroshima bombing are clear because of public statements that have been made by major participants, and by indisputable documents and recordings. 1. Though having been militarily defeated throughout much of their empire, the Japanese government refused the surrender terms (Potsdam Declaration) presented by the Allied Forces ( the USA, UK and China). The Japanese government was in a stalemate between the military leaders who advocated continuing to fight at all costs and against all odds, and civilian leaders who advocated negotiating an end to the war. The Emperor sided with the military. Civilians were being trained to partipate in the repulsion of invasion, foreshadowing the suicide bombers of today's terrorist groups. 2. US President Truman, having consulted with military, diplomatic and political advisors, was convinced that bringing the war to a swift conclusion would save far more lives (both military and civilian) than those that would be lost to the two nuclear bombs that the US possessed. Not all of his advisors agreed; the decision was in his hands alone. He was convinced that continuing conventional warfare would cost at least hundreds of thousands of Allied casualties and millions of civilian casualties. An invasion could not have been conducted without intensive conventional bombing and a blockade that would have caused massive starvation. Meanwhile, warfare was continuing in China and tens of thousands were dying there each month.

Answer 3

the war was growing very violent very fast, so America decided to use it's most powerful weapon then, the atomic bomb.

it wasn't dropped on factories because it wasn't dropped to hurt, it was dropped to scare.

Answer 4

A desperate search by the US to bring the war to a close.

Answer 5

President Truman stated the he needed to end the war and to collapse Japan's means to make war ever again.