The U.S. purported to not want to get involved in the conflict in Europe at all. They were essentially drug into the Pacific theater after the bombing of Pearl Harbor (or at least given a good excuse to enter), but why did that necessitate getting involved in Europe at the same time as well?
I know Japan was officially allied w/ Germany and Italy, but could they not have been treated as separate conflict?
Germany declared war on the US on Dec 11th, hard to ignore that.
It was also agreed policy between FDR and Churchill to try to tackle Europe first as Germany presented the more immediate threat, and if the UK fell in Europe then no aid could be given in India and the Pacific, and if Russia fell there was nothing good that would come of it.