Roosevelt and Eisenhower
some countries
Germany & Italy were allied to Japan in WWII.
UKFrance
Yes it is
The austro hungarians allied with germany.
There were over a hundred countries that were not part of World War I.
In World War I Australia fought with other countries but in World War II they were not part of the Allied Forces that conquered the Axis Forces.
There's a misunderstanding here. Concentration camps did not lead to World War 2. Countries went to war for much more down to earth reasons. In fact, liberating concentration camps didn't figure anywhere in Allied war aims.
No they couldn't have avoided it.
France and England
Germany, Japan and Italy were allied. Britain, France, U.S.A and Russia were allied.
It was not simply two countries, but it was the Axis and Allied Powers.