The country that suffered the most military deaths, by far, during World War II was the Soviet Union, not Japan, Germany, or the United States. The Soviet Union faced unparalleled casualties during the conflict, with estimates ranging from around 8 to 10 million military deaths, representing a substantial portion of the overall human cost of the war. While Japan, Germany, and the United States all experienced significant military losses during the war, it was the Soviet Union that bore the heaviest burden in terms of military casualties, reflecting the immense scale of the Eastern Front and the fierce fighting that took place on Soviet soil throughout the war.