This paper, by MAJ Thomas M. McGinnis, USA, 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 Jomin' 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.
