WWII's A-Bomb Controversy

The main reasons behind dropping the atomic bombs on Hiroshima and Nagasaki were to avoid invasion and American casualties. With the invention of this new weapon, why would we risk invading Japan when we can just drop a weapon of mass destruction? These reasons seemed logical at the time, but after watching NBC's video about these A-bombs, the results for the Japanese were devastating. The ideal of the American citizen was to win war in a respectful, fair, and proud manner. Had US citizens seen this video during the war (or even shortly after the war had ended), they may have questioned the integrity of their victory as a nation, leading to potential nationwide decrease in nationalism.