▁directly ▁challeng ing ▁threaten ing ▁Japan ' s ▁hold ▁on ▁the ▁recently ▁established ▁pu ppet ▁state ▁of ▁Man ch u ku o . ▁ ▁The ▁end ▁of ▁the ▁Anti - J apan ese ▁Al lied ▁Army ▁ ▁Chi ang ▁K ai - she k ▁believed ▁that ▁commun ists ▁domin ated ▁the ▁Anti - J apan ese ▁Al lied ▁Army , ▁and ▁felt ▁that ▁it ▁was ▁a ▁threat ▁to ▁his ▁authority . ▁ ▁When ▁the ▁Anti - J apan ese ▁Al lied ▁Army ▁was ▁proc laimed , ▁the ▁Ku om int ang ▁military ▁committee ▁in ▁P ek ing ▁issued ▁an ▁order ▁to ▁cut ▁off ▁passenger ▁train ▁service ▁to ▁Kal gan . ▁ ▁Later ▁they ▁sent ▁an ▁arm ored ▁train ▁close ▁to ▁Kal gan , ▁and ▁directed ▁Yan ▁X ish an ▁to ▁station ▁troops ▁on ▁the ▁Sh an xi ▁border ▁with ▁Ch ah ar , ▁including ▁the ▁ 4 2 nd ▁Division ▁under ▁F eng ▁Q in za i , ▁Chinese ▁ 3 5 th ▁Army ▁under ▁Fu ▁Zu oy i ▁and ▁Chinese ▁ 3 rd ▁Army ▁under ▁P ang ▁B ing x un . ▁ ▁In ▁July ▁the ▁Chinese ▁ 1 7 th ▁Army ▁under ▁X u ▁T ing ya o ▁and ▁ 8 7 th ▁Division ▁under ▁Wang ▁J ing ji u ▁rel ieved ▁the ▁forces ▁of ▁Sun ▁D ian ying ▁and ▁took ▁control ▁of ▁the ▁Pe ik ing ▁- ▁S ui y uan ▁rail ▁line , ▁prevent ing ▁outside ▁supply ▁and ▁rein for cement ▁to ▁the ▁Anti - J apan ese ▁Al