Nuclear weapons were first developed in the United States during the Second World War, to be used against Germany. However, by the time the first bombs were ready for use, the war with Germany had ended and, as a result, the decision was made to use the weapons against Japan instead. Hiroshima and Nagasaki have suffered the consequences of this decision to the present day.
The real reasons why bombs were dropped on two heavily-populated cities are not altogether clear. A number of people in 1944 and early 1945 argued that the use of nuclear weapons would be unnecessary, since American Intelligence was aware that some of the most powerful and influential people in Japan had already realized that the war was lost, and wanted to negotiate a Japanese surrender. It was also argued that, since Japan has few natural resources, a blockade by the American navy would force it to surrender within a few weeks, and the use of nuclear weapons would thus prove unnecessary. If a demonstration of force was required to end the war, a bomb could be dropped over an unpopulated area like a desert, in front of Japanese observers, or over an area of low population inside Japan, such as a forest. Opting for this course of action might minimize the loss of further lives on all sides, while the power of nuclear weapons would still be adequately demonstrated.
All of these arguments were rejected, however, and the general consensus was that the quickest way to end the fighting would be to use nuclear weapons against canters of population inside Japan. In fact, two of the more likely reasons why this decision was reached seem quite shocking to us now.
Since the beginning of the Second World War both Germany and Japan had adopted a policy of genocide (i. e. killing as many people as possible, including civilians). Later on, even the US and Britain had used the strategy of fire bombing cities ( Dresden and Tokyo, for example) in order to kill, injure and intimidate as many civilians as possible. Certainly, the general public in the West had become used to hearing about the deaths of large numbers of people, so the deaths of another few thousand Japanese, who were the enemy in any case, would not seem particularly unacceptable--a bit of "justifiable" revenge for the Allies’ own losses, perhaps.
The second reason is not much easier to comprehend. Some of the leading scientists in the world had collaborated to develop nuclear weapons, and this development had resulted in a number of major advances in technology and scientific knowledge. As a result, a lot of normal, intelligent people wanted to see nuclear weapons used; they wanted to see just how destructive this new invention could be. It no doubt turned out to be even more "effective" than they had imagined.
It is implied in the passage that western people at the time
A．were indifferent to the deaths of the civilians in an enemy country.
B．were sympathetic with the deaths of the Japanese civilians.
C．were taking a justifiable revenge on the Japanese troops.
D．were intimidated when hearing about the death in Japan.