A decade or two earlier, this would have been unthinkable. The planes, for one, had been too small. The biggest planes in operation in World War I had been the German Riesenflugzeug (“giant aircraft”), most notably the Siemens-Schuckert planes, the largest of which could hold two and a half tons—the Germans had built six during the war. But by the end of the Second World War, the United States had produced nearly four thousand B-29 Superfortresses, each of which could carry twenty tons.
