▁the ▁invasion ▁caught ▁the ▁Soviet ▁military ▁un prep ared . ▁ ▁In ▁the ▁larger ▁sense , ▁St alin ▁expected ▁invasion ▁but ▁not ▁so ▁soon . ▁The ▁Army ▁had ▁been ▁dec im ated ▁by ▁the ▁P urg es ; ▁time ▁was ▁needed ▁for ▁a ▁recovery ▁of ▁compet ence . ▁As ▁such , ▁mobil ization ▁did ▁not ▁occur ▁and ▁the ▁Soviet ▁Army ▁was ▁tact ically ▁un prep ared ▁as ▁of ▁the ▁invasion . ▁The ▁initial ▁weeks ▁of ▁the ▁war ▁were ▁a ▁dis aster , ▁with ▁tens ▁of ▁thousands ▁of ▁men ▁being ▁killed , ▁wounded , ▁or ▁captured . ▁Wh ole ▁divisions ▁dis integr ated ▁against ▁the ▁German ▁on s la ug ht . ▁ ▁German ▁troops ▁reached ▁the ▁out sk ir ts ▁of ▁Moscow ▁in ▁December ▁ 1 9 4 1 , ▁but ▁failed ▁to ▁capture ▁it , ▁due ▁to ▁sta unch ▁Soviet ▁defence ▁and ▁counter att acks . ▁At ▁the ▁Battle ▁of ▁St aling rad ▁in ▁ 1 9 4 2 – 4 3 , ▁the ▁Red ▁Army ▁inf lic ted ▁a ▁cr ushing ▁defeat ▁on ▁the ▁German ▁army . ▁ ▁Due ▁to ▁the ▁unw illing ness ▁of ▁the ▁Japanese ▁to ▁open ▁a ▁second ▁front ▁in ▁Man ch uria , ▁the ▁S ovi ets ▁were ▁able ▁to ▁call ▁do z ens ▁of ▁Red ▁Army ▁divisions ▁back ▁from ▁eastern ▁Russia . ▁These ▁units ▁were ▁instrument al ▁in ▁turning ▁the ▁t ide , ▁because ▁most ▁of ▁their ▁officer ▁corps ▁had ▁escaped ▁St alin ' s ▁p urg es . ▁The ▁Soviet ▁forces ▁soon ▁launched ▁massive ▁counter