Jomini and the Ardennes: An Analysis of Lines of Operation and Decisive Points

This paper examines the applicability of the theories of the 19th Century military theorist, Baron Antoine Henri Jomini, to modern 20th century mid- to high intensity conflict. To do this it briefly reviews the core of Jomini‘s most famous work, The Art of War. It then tests two key Jominian concepts, lines of operation and decisive points, against the reality of a major 20th century operation, the German counteroffensive in the Ardennes in December 1944. The study first sets the strategic and operational setting then traces the general conduct of the operation from the corps and army perspective. The first phase studied is the German offensive and American defensive from 16 December to 26 December 1944. The second is the American offensive and German defensive from 22 December 1944 to 28 January 1945. In the theoretical analysis of these two phases, the paper examines the applicability of lines of operation and decisive points for planning and conduct of major offensive and defensive operations. It concludes that both armies and their commanders applied these two concepts throughout the planning and conduct of their operations. Such extensive application indicates that these two Jominian concepts still have utility for the modern operational commander.