Originally Posted by
bulldog89
It wasn’t to “save Europe” but to limit Japanese expansion in the East (do not forget about US economical and political interests in the SE) and to avoid the conquest of the entire Europe by Germany and/or the USSR. You can see all of this had huge geopolitical and economical reasons behind it.
So much better put than my somewhat facetious post. It's perhaps also worth mentioning that it was also one of Roosevelt's aims to break up the British Empire.