Had sufficient time and resources been devoted to the project at a point in time early enough, an "Amerikabomber" may have become operational before the war's end. However, as historian James P. Duffy pointed out, Nazi Germany had no central authority for the development and construction of advanced weaponry, including new aircraft concepts and designs, as well as critical problems in developing high-powered aviation engines – that is, with output of over 1,500 kW (2,012 hp) each, which could operate reliably in combat conditions – that would have been required. Hitler was often swayed to waste time, money and resources on new "miracle weapons" and other projects that were unlikely to be successful. The "Amerikabomber" project was not one of the projects so favored. In addition, Allied bombing became so intense during the middle of the war that it disrupted critical German supply chains, particularly fuel; in addition, ever-greater proportions of resources were reserved for home defense purposes. German scientists were forced more and more to compete for ever scarcer resources. Together, all of the above political and strategic constraints made construction of such an aircraft increasingly less likely.