Why the allies won

It is 1942. Germany controls almost the entire resources of continental Europe and is poised to move into the Middle East. Japan has wiped out the western colonial presence in East Asia in a couple of months and is threatening northern India and Australia. The Soviet Union has lost the heart of its industry, and the United States is not yet armed. Democracy has had its day.
The Allied victory in 1945 has since come to seem inevitable. It was not. In Richard Overy's incisive analysis, we see exactly how the Allies regained military superiority and why they were able to do it. Overy offers a brilliant analysis of the decisive campaigns: the war at sea, the crucial battles on the eastern front, the air war, and the vast amphibious assault on Europe. The eastern front was critical. Having lost four million men and tens of thousands of tanks and aircraft in the first six months of fighting, the Soviet Union was able to relocate its industrial base to the east, intensify its industrial production, and defeat the German forces at Stalingrad and Kursk. This was the turning point, the victory of one authoritarian system over another.
Overy also explores the deeper factors affecting military success and failure: industrial strength, fighting ability, the quality of leadership, and the moral dimensions of the war.