A professional army stands next to a professional civil service as an institutional standard of the modern state. In the late nineteenth century, the Prussian army emerged as the undisputed model of military professionalism. With lightning-fast victories over Denmark, Austria, and France, the Prussians redefined the concept of warfare. The key to their success was a mass citizen army that was rigorously trained in peacetime, readied for immediate mobilization, and commanded by a highly educated and centrally coordinated cadre of staff and line officers. This form of military organization made possible short, decisive wars, and it put a premium on long-term peacetime preparation, comprehensive planning, and professional leadership.

By the 1880s, the basic principles of the Landwehr had been adapted to indigenous military traditions in France, Russia, Austria, Italy, and the minor continental states. The Prussian model was also the standard for professional army reformers in Great Britain and America, but in terms of actual structural changes, these more isolated states lagged behind those of the Continent.