Those officers who had either closely observed or studied the German failure in World War I attributed that nation’s defeat to its economic vulnerability—its relative lack of raw materials and its inability to withstand the Allied naval blockade. Japan, they gloomily recognized, was far less well-endowed than Germany. Indeed, it faced a unique problem of supply. It was almost bare of the resource of oil. While petroleum held a relatively small place in the country’s energy mix—accounting for only about 7 percent of total energy consumption—its significance was in its strategic importance.
