World War II Just War Theory
The American's original intentions of the United States entry into war were justified, but because the intentions changed throughout the war makes their actions unjust. The Just War Theory gave several names to war strategies that kept the war just or on track to solving what was initially intended and keeping fair actions. It states that you do what ever you can to remain fair. Thomas Aquinas believed that by the end on the war, the reasons for fighting were not the same as the original intentions.Germans sank numerous American merchant ships and took the supplies to England, Japan demanded unreasonably on the United States (for example they re-instated oil sales and dropped the support of the Philippines and China), German submarines began to shoot at American war ships, and Pearl Harbor were some of the key reasons for entering the war. Anytime we are attacked it was a leading act to joining this inevitable war. However, realize that we declared war on Japan and three days later Germany declared war on us was not a coincidence.
What the Americans later began to fight for was to be an alliance to England and France. This is unjust because initially we waned to fight the Japanese and German because they insisted war. In becoming allies with France and England, we had taken the spot light off of ourselves and put it directly onto our allies. Since England and France both have strong armies, it was not an issue for them to fight (especially with a few extra men from the American troops).
The Americans joined the war for one reason. Their reasoning for joining the war in the first place was still in mind, but has been expanded and tweaked. Their actions became unjust for giving one reason to go to war, but fighting for something else.