Answer:
US forces fought in Europe together with Great Britain, Canada, France and other allies in the Western Front against Nazi Germany and her allies. At the same time, it fought against the Japanese in the Pacific. So, it was a two-front war for American armed forces. In neither of them there was a defined line for a long time (just as it had hapened in WWI). Because the campaign involved air, naval and land battles or operations, it is a war fought on multiple fronts in both the Pacific and the European theaters.
Step-by-step explanation: