Kammala jumla mai zuwa: A cikin 1815 Legion na Rasha da Jamusanci sun haɗu da Sojojin Prussian kuma Clausewitz ya sake shiga aikin Prussian a matsayin colonel. Ba da daɗewa ba aka nada shi shugaban ma'aikatan Johann von Thielmann na III Corps. A wannan matsayin ya yi aiki a yakin Ligny da yakin Wavre a lokacin yakin Waterloo a 1815. Sojojin da Napoleon ya jagoranci da kansa sun ci Prussians a Ligny (kudu da Mont-Saint-Jean da ƙauyen Waterloo) a ranar 16 ga Yuni 1815, amma sun janye cikin tsari mai kyau. Rashin nasarar Napoleon na lalata sojojin Prussian ya haifar da rashin nasararsa 'yan kwanaki bayan haka a yakin Waterloo (18 ga Yuni 1815), lokacin da sojojin Prussian suka isa gefensa na dama da yamma don tallafawa sojojin Anglo-Dutch-Belgium da ke matsawa gabansa. Napoleon ya shawo kan sojojinsa cewa rigunan fararen filin sune na Grenadiers na Marshal Grouchy. Ƙungiyar Clausewitz ta yi yaƙi da yawa a
Wavre (18<unk>19 Yuni 1815), yana hana manyan ƙarfafawa daga isa Napoleon a Waterloo. Bayan yakin, Clausewitz ya yi aiki a matsayin darektan "Kriegsakademie", inda ya yi aiki har zuwa 1830. A wannan shekarar ya koma aiki tare da sojojin. Ba da daɗewa ba bayan haka, juyin juya hali da yawa a Turai da kuma rikici a Poland ya nuna cewa za a sake yin wani babban yaƙi a Turai. An nada Clausewitz a matsayin shugaban ma'aikatan rundunar soja guda daya da Prussia ta iya tattarawa a cikin wannan gaggawa, wanda aka aika zuwa iyakar Poland. Kwamandansa, Gneisenau, ya mutu ne daga cutar kwalara (Agusta 1831), kuma Clausewitz ya dauki umurnin kokarin sojojin Prussian don gina ginin da ke dauke da cutar kwalara (a karo na farko da cutar kwalara ta bayyana a cikin Turai na zamani, wanda ya haifar da tsoro a fadin nahiyar). Clausewitz da kansa ya mutu daga wannan cutar jim kaɗan bayan haka, a ranar 17 ga Nuwamba 1831.