“To establish a proper manpower balance for the United States in wartime was as difficult as it was important. The absolute ceiling on the number of men physically fit for active military service was estimated to be between fifteen and sixteen million. On the surface it was hard to understand, in the light of the available manpower pool, why there should be any U.S. manpower problem at all. Why, if Germany could maintain a military establishment of 9,835,000 or 10.9 percent of her population and Britain could support 3,885,000 or 8.2 percent of hers, did the United States manpower officials insist in late 1942 that 10,500,000 or only 7.8 percent would be the maximum force that the country could sustain without incurring serious dislocation to the American economy? The problem as well as the answer stemmed basically from the fact that the Allies had from the beginning accepted the proposition that the single greatest tangible asset the United States brought to the coalition in World War II was the productive capacity of its industry. From the very beginning, U.S. manpower calculations were closely correlated with the needs of war industry. The Army had therefore to compete for manpower not only with the needs of the other services but also with the claims of industry.” – Maurice Matloff, Strategic Planning for Coalition Warfare:1943-1944