In 2009, David Stahel wrote that the Clausewitzian culminating point (a theoretical watershed at which the strength of a defender surpasses that of an attacker) of the German offensive occurred before the Battle of the Marne, because the German right (western) flank armies east of Paris, were operating 100 kilometers from the nearest rail-head, requiring week-long round-trips by underfed and exhausted supply horses, which led to the right wing armies becoming disastrously short of ammunition.