The Changing Nature of Warfare:
The Atomic Bombing of Hiroshima and Nagasaki
Focus Question:
Why did the dropping of the atomic bombs end World War II?
Overview:
The United States detonated two atomic
bombs over the Japanese cities of Hiroshima and Nagasaki in August 1945, killing 210,000 people
—children, women, and men.
President Truman authorized the use of the atom bombs to bring about Japan’s surrender in
the Second World War. In the days following the bombings Japan surrendered.
The Manhattan Project was the US government program during World War II that developed and
built these first atomic bombs.
Detonation of these first nuclear bombs signalled arrival of a frightening new Atomic Age.
The Manhattan Project
The Manhattan Project was the codename for the secret US government research and
engineering project during the Second World War that developed the world’s first nuclear
weapons. President Franklin Roosevelt established a committee, called The Advisory Committee
on Uranium to look into the possibility of developing a nuclear weapon after he received a letter
from Nobel Prize laureate Albert Einstein in October 1939. In his letter, Einstein warned the
president that Nazi Germany was likely already at work on developing a nuclear weapon . By
August 1942, the Manhattan Project was underway. By 1943, there were more than 100 000
scientists, engineers and clerks across the United States who were working on The Manhattan
Project and in July 1945, the first atomic bomb was tested successfully in New Mexico.
The Ultimatum
In May 1945, the Allies defeated Germany, two months before the atomic bomb was complete.
War with Japan continued, however, and In August 1945 it seemed that an invasion of Japan itself
might be necessary to force the Japanese to surrender. Military advisers to President Harry S.
Truman warned that such a ground war would result in the deaths of tens or hundreds of
thousands of young men in the US Armed Forces, as well as the deaths of many Japanese military
personnel and civilians. Truman believed that that the atomic bomb was the only way to end
World War II quickly and force Japan’s unconditional surrender. After receiving no reply to his
The Atomic Bombing of Hiroshima and Nagasaki
Focus Question:
Why did the dropping of the atomic bombs end World War II?
Overview:
The United States detonated two atomic
bombs over the Japanese cities of Hiroshima and Nagasaki in August 1945, killing 210,000 people
—children, women, and men.
President Truman authorized the use of the atom bombs to bring about Japan’s surrender in
the Second World War. In the days following the bombings Japan surrendered.
The Manhattan Project was the US government program during World War II that developed and
built these first atomic bombs.
Detonation of these first nuclear bombs signalled arrival of a frightening new Atomic Age.
The Manhattan Project
The Manhattan Project was the codename for the secret US government research and
engineering project during the Second World War that developed the world’s first nuclear
weapons. President Franklin Roosevelt established a committee, called The Advisory Committee
on Uranium to look into the possibility of developing a nuclear weapon after he received a letter
from Nobel Prize laureate Albert Einstein in October 1939. In his letter, Einstein warned the
president that Nazi Germany was likely already at work on developing a nuclear weapon . By
August 1942, the Manhattan Project was underway. By 1943, there were more than 100 000
scientists, engineers and clerks across the United States who were working on The Manhattan
Project and in July 1945, the first atomic bomb was tested successfully in New Mexico.
The Ultimatum
In May 1945, the Allies defeated Germany, two months before the atomic bomb was complete.
War with Japan continued, however, and In August 1945 it seemed that an invasion of Japan itself
might be necessary to force the Japanese to surrender. Military advisers to President Harry S.
Truman warned that such a ground war would result in the deaths of tens or hundreds of
thousands of young men in the US Armed Forces, as well as the deaths of many Japanese military
personnel and civilians. Truman believed that that the atomic bomb was the only way to end
World War II quickly and force Japan’s unconditional surrender. After receiving no reply to his
