Hague Convention

The first two Hague Conventions, in 1899 and 1907 were the first establishment of international law regarding war, or otherwise. At these conventions powers of the world attended such as: The United States, Britain, France, and Russia. These countries drafted and voted on laws that would come to be understood around the world, but not completely followed. The U.S. directly violated one of these when dropping the atomic bombs on Japan.

Article 25 of Section II of the IV Annex to the Convention states,

"The attack or bombardment, by whatever means, of towns, villages, dwellings, or buildings which are undefended is prohibited."

That is simple enough. Nagasaki and Hiroshima were not being defended. There was no opposition to our planes. They flew over the radar, and dropped a bomb first, onto a military base. Then, onto an industrial area that consisted mostly of civilians. 

The Peace Palace, The international court house in which the
Hague Convention was held. It is located in The Netherlands. 

During its time, the Hague Convention was considered highly
important and it still is to this day. The rules that were established
are followed by a majority of the countries on the Earth.

Though the United States isn't the only country that violated the Hague Convention, but we are considered the most powerful country in the world and we were then. In violating this somewhat universally accepted document, we have shown disrespect to it, and set a horrible example for the rest of the countries around the world, and possibly gave an excuse to some of the more, misguided countries of the world. The agreements made at the Hague Convention should always be respected, and every country that violates them should be held accountable for, victory or not. The Laws of War that were established at the Hague Convention can be read here.