The Allies played a crucial role in the defeat of Nazi Germany by coordinating large-scale military operations across multiple fronts during World War II. Key operations, such as the D-Day invasion in 1944, were pivotal in liberating occupied Europe. The combined forces of the United States, the Soviet Union, and the United Kingdom, among others, overwhelmed German troops both in Western Europe and on the Eastern Front. The relentless pressure of Allied offensives, coupled with the strategic bombing of German industrial sites, crippled Nazi war efforts, ultimately leading to Germany's surrender in May 1945.