▁prisoners , ▁but ▁after ▁ 1 9 3 9 , ▁political ▁prisoners ▁began ▁to ▁dis place ▁the ▁criminal ▁prisoners , ▁though ▁crim inals ▁were ▁preferred ▁by ▁the ▁SS . ▁Political ▁prisoners ▁took ▁over ▁important ▁positions ▁as ▁" pr ison er ▁function aries " ▁until ▁liber ation . ▁The ▁criminal ▁function aries ▁were ▁known ▁for ▁their ▁brut ality , ▁which ▁they ▁used ▁in ▁order ▁to ▁impress ▁the ▁SS ▁gu ards ▁and ▁improve ▁their ▁own ▁lot . ▁They ▁were ▁h ated ▁by ▁other ▁prisoners , ▁who ▁were ▁eventually ▁able ▁to ▁bring ▁them ▁down ▁by ▁un cover ing ▁evidence ▁of ▁the ft ▁from ▁camp ▁w are h ouses . ▁ ▁After ▁the ▁German – S ov iet ▁non - ag gression ▁treat y ▁of ▁August ▁ 1 9 3 9 , ▁the ▁ide ological ▁ant agon ism ▁between ▁the ▁Naz is ▁and ▁the ▁Commun ists ▁was ▁tempor arily ▁m oll ified . ▁The ▁SS ▁knew ▁that ▁Commun ists ▁were ▁able ▁to ▁organ ize ▁people ▁and ▁that ▁they ▁had ▁an ▁international ▁network , ▁which , ▁from ▁the ▁point ▁of ▁view ▁of ▁the ▁concentration ▁camp ▁direction , ▁was ▁useful ▁because ▁after ▁the ▁start ▁of ▁the ▁war , ▁Buch en wald ▁had ▁a ▁mult iling ual ▁prisoner ▁population . ▁When ▁Germany ▁later ▁inv aded ▁the ▁Soviet ▁Union ▁in ▁ 1 9 4 1 , ▁the ▁Commun ist ▁prisoners ▁at ▁first ▁lost ▁these ▁positions , ▁but ▁later ▁managed ▁to ▁win ▁them ▁back . ▁To ▁strength en ▁camp ▁coh es ion , ▁the ▁Commun ist ▁kap os ▁made ▁sure ▁that ▁prisoner