What arguments could be made for using atomic bombs to end the war? What arguments could be made against using atomic weapons in the war?

The main argument in support of the decision to use the atomic bomb is that it saved American lives which would otherwise have been lost in two D-Day-style land invasions of the main islands of the Japanese homeland

1. the loss of the life would have been greater if the conventional invasion of Japan occurred.

japan seemed unwilling to surrender even in the face of almost certain defeat without an overwhelming show of force.

2. it would be immortal to kill civilians who would inevitably be killed in such an attack.

using such a weapon would simply encourage other countries to develop such weapons - this would endanger the whole world