To claim that any one device won the war is reductive and narrows the focus too tightly when considering a global war. Each item on its own contributed to the

To claim that any one device won the war is reductive and narrows the focus too tightly when considering a global war. Each item on its own contributed to the war effort, absolutely. The cavity magnetron and the RADAR it enabled saved lives in the Battle of Britain, the PTO and elsewhere thanks to its early warning of incoming air raids, to be sure. To claim any single item was decisive is pretty tough, though, when compared against broader concepts like disparity in industrial base, logistical ability, and so on. To the T-34 example you quote, how well would the T-34 have performed without locomotives to bring fuel, consumables, and the tanks themselves to the front? Or the resources to the tank factories in the first place?