"That the General Staff succeeded in preserving the lessons learned at such cost in the struggle against Napoleon, was to a large extent the work of Clausewitz. Among the whole group of the Reformers, Clausewitz had been from the outset the theoretician par excellence. Not in the sense of a one-sided abstract academic pedant, but as a practical soldier, who at the same time happened to be that rare phenomenon, a natural born theorist; combining a keen appreciation of the requirements of a sound theory, with a unique understanding of the practical uses to which it could be put. During the wars against Napoleon a series of mishaps kept Clausewitz in relatively subordinate positions incommensurate with his exceptional abilities. After the peace had been reestablished, he was confined for twelve dreary years, from 1818 to 1830 to a purely administrative post as military director of the War Academy in Berlin. There, out of the intense feeling of frustration that forced him to seek an outlet for his gifts and energies in his private studies arose a long series of military studies, culminating in his famous treatise On War, the most profound, comprehensive, and systematic examination of war that has appeared to the present day."