Atomic Justification.

As a result of the harsh conditions Germany was left in after World War I, many extremist organizations aroused, one being the National Socialist German Workers Party, or the Nazis. The Nazis were led by Adolph Hitler; Hitler was willing to conquer many territories. Britain and France satisfied Hitler's demand for territories at the Munich Conference, were Germany was allowed to control Sudetenland, in former Czechoslovakia. Through this agreement, Britain and France hoped for Hitler's territorial ambitions to come to an end. Unfortunately they made a mistake. Germany continued its path until the finally conquered Poland, thus starting WWII in Europe. Further on other nations such as Japan and Italy were fighting along with Germany against the rest of the world. Particularly, United States' relations with Japan deteriorated greatly. Trade with Japanese was cut off , resulting in Japanese madness. Europe's Axis powers were defeated first, and the remaining Japanese nation was left, it corresponded the U.S. to take care of the Japanese, after all they were attacked by the Japanese in the Pearl Harbor incident. An so they did in 1945, in a very harsh but necessary, and justified way. The U.S. resorted to using the powerful atomic bombs which fell on Hiroshima and Nagasaki. The U.S. was justified in dropping the bombs because if they never did so, the number of casualties could have been even bigger if trying to invade Japan. In addition, the Japanese may have never surrendered. Plus the costly and savage battles at Okinawa and Iwo Jima were motives to drop the bomb which would result in less casualties.
Truman decide to use the atomic bombs on Japan because if he decided to go along with the already planed Operation Downfall which purpose was to invade Japan, the number of casualties could have been larger on both the Japanese and American side. In case of invasion attempt, the Japanese were willing to use women and children to fight. Additionally, Japan battled by using total war, meaning that ever single available resource was used against the enemy. This also meant that many civilians from around the world were in greater danger since the war would have last longer.
Japan's fighters fought with great honor and pride, this made the battle for the allies even harder. Japanese culture taught its people to never surrender no matter what. The Japanese were willing to fight till the very end, so a formal agreement with Japanese leaders to end battle was hardly possible. The pride of the Japanese can be seen in many action. One was the kamikaze pilots or suicide pilots that did not want to die without making any damage to the enemy. In addition, many Japanese leaders committed suicide rather than to be captured and prosecuted and most likely executed. The dropping of the bombs was necessary to make the Japanese surrender.
The U.S. did not want the same thing for the many Americans who lost their lives due to the fierce battles of Okinawa and Iwo Jima. The bombs were necessary to lessen the casualties. Having to battle at Japan was very dangerous due to the battle methods of the Japanese. The bombs were necessary to save millions of lives that could been lost at battle even bigger than Iwo Jima and Okinawa.
The United States made a justified decision in dropping the atomic bombs at Hiroshima and Nagasaki. They did it in order to save the rest of humanity threatened by the strong minded Japanese fighters. This was the only way to force the Japanese to surrender, since when the allies offered a conditional surrender the Japanese objected the offer. The bombs were successful in making the Japanese surrender. More importantly it ended World War II.