EmperorNero and
afronappy,
According to
http://www.historyplace.com/worldwar2/holocaust/timeline.html, the first mass-murder of Jews did not occur until
July, 1941. The United States was already giving away massive amounts of money, supplies, and military hardware, and at the same time building up its own armies for eventual entry into the war. The first mass gas chamber executions did not begin until January, 1942, after the United States had
already entered the war.
If you take the time to read that timeline, you'll clearly see that most of the genocide happened during the second half of the war. There was a lot of public outcry to help the European Jews, but all of the countries involved were busy fighting Germany and Japan. The only way to help the people in the concentration camps was to defeat Germany, which took almost 6 years. On top of that, the worst of the attrocities we know about now were not even known until the waning days of the war.
The United States, both unaware of the severity of the situation, and
unable to fight a large scale war, spent years building up its militarty and entered the war as soon as it was ready. The American military was not powerful enough to fight a large scale war until 1941.
Learn some of the history, and take the time to note the important dates. Then tell me what else could possibly have been done, with the knowledge the world had at the time. It was an unspeakable human tragedy, and in hindsight Hitler should have been stopped before he had complete power. How was the world supposed to know what would happen, though?