From Jomini to Dennis Hart Mahan: The Evolution of Trench Warfare and the American Civil War

FROM JOMINI TO DENNIS HART MAHAN: The Evolution of Trench Warfare and the American Civil War Edward Hagerman I The transition from fluid strategic and tactical movement in the early campaigns of Napoleon to the trench warfare of the American Civil War began in the period of the Empire and the Restoration. During the period of transition and theory, from the end of the Napoleonic Wars to the wars of the mid-nineteenth century, the Empire and Restoration generation of military writers interpreted the Napoleonic campaigns, and the succeeding generation of American theorists modified their conclusions, in response to peculiarly local circumstances , technological change, and a number of indecisive wars. Reflecting the milieu in which it arose, the military thought of the post-Napoleonic generation of continental synthesizers was cautious and conservative, more concerned with codification than with innovation . Rejected were the innovational military outlook and theories of the French Revolutionary reformers, led by Bourcet and Guibert, as was Napoleon's application of their theories in his campaigns. The Revolutionary reformers had been preoccupied with strategic and tactical mobility, pursuing victory through flexibility in strategic and tactical maneuver. The new orthodoxy of the post-Revolutionary generation rejected strategic maneuver in favor of a concentrated and direct strategic approach on the decisive point in the enemy's line. Primarily responsible for this transformation was Antoine Henri Jomini. His writings between 1804 and 1839 set the dominant trend in continental and American strategic thought until German victories in 1870 pushed Clauswitz's interpreters to the center of the continental stage. Born in 1779, Jomini missed the fervor of the Revolutionary generation. He came to intellectual maturity during the Empire and Restoration, a period of codification and quest for stability in all spheres of social activity, including the waging of war. Jomini's first exposure to war came as a staff officer in Napoleon's armies during the Empire, by which time the Revolutionary tradition 197 198civil war history of mobility, dispersion, diversion, and surprise had largely given way in the French armies to the direct strategic approach, with ultimate dependence upon mass and the frontal assault. Jomini's quest for a valid tactical and strategic system also reflects an acknowledged debt to Frederick the Great and an unacknowledged debt to Frederick's eighteenth-century English interpreter, Henry Lloyd. The concepts Jomini set forth in his first work, Treatise on Great Military Operations (1804-1816), for example, were plagiarisms, sometimes wordfor -word, from Lloyd's The History of the Late War in Germany: Between the King of Prussia and the Empress of Germany and her Allies , written between 1776 and 1790. Throughout his writings Jomini tended to evaluate Napoleon by Frederick's standards.1 Like the Revolutionary reformers, Jomini considered the cutting of an opponent's lines of communication by strategic maneuver by a highly mobile army the most desirable way to wage war. But he considered strategic maneuver, and particularly battlefield flanking maneuvers , so difficult to execute that they could not be depended upon except where particularly advantageous conditions prevailed. Napoleon possessed the genius to make the strategic concepts of the reformers work. But Napoleons, as Jomini knew, were rare. And even Napoleon, Jomini discovered, confronted problems that made mass generally more attractive than maneuver. Under normal circumstances Jomini advocated what he considered the less desirable but more dependable recourse to a direct and concentrated strategic approach with ultimate dependence on the massed frontal assault. Ultimate dependence upon an offensive tactical solution involved the risk of positional stalemate and the specter of trench warfare should technological or other developments shift the tactical balance to the defensive, and should strategic maneuver subsequently not be restored. The changing nature of warfare did not completely undermine the primacy of the frontal assault and with it the viability of the direct strategic approach until the American Civil War. But the transition that was to lead to the Civil War experience, together with the theoretical preparation for the transition, began in the same generation that produced the Jominian orthodoxy. American tactical thought was not so ill prepared for the changed conditions of warfare in the American Civil War as historians generally assume. American tactical and strategic thought...