Between August and October 1943 American warplanes repeatedly bombed Schweinfurt, in southern Germany. The Bavarian town did not host army HQs or a major garrison. But it produced half of the Third Reich’s supply of ball bearings, used to keep axles rotating in everything from aircraft and tank engines to automatic rifles. To Allied planners, who had spent months studying the input-output tables of German industry, the minuscule manufacturing part had the trappings of a strategic commodity. Knock away Germany’s ability to make them, the thinking went, and its military-industrial complex would come crashing down.
Source: Finance - economist.com