1 9 7 9 ▁attack ▁confirmed ▁H ano i ' s ▁per ception ▁of ▁China ▁as ▁a ▁threat . ▁The ▁P AV N ▁high ▁command ▁hence for th ▁had ▁to ▁assume , ▁for ▁planning ▁purposes , ▁that ▁the ▁Chinese ▁might ▁come ▁again ▁and ▁might ▁not ▁halt ▁in ▁the ▁fo oth ills ▁but ▁might ▁drive ▁on ▁to ▁H ano i . ▁The ▁border ▁war ▁strength ened ▁Soviet - V ietnam ese ▁relations . ▁The ▁Soviet ▁military ▁role ▁in ▁Vietnam ▁increased ▁during ▁the ▁ 1 9 8 0 s ▁as ▁the ▁S ovi ets ▁provided ▁arms ▁to ▁Vietnam ; ▁moreover , ▁Soviet ▁ships ▁enjoyed ▁access ▁to ▁the ▁har b ors ▁at ▁Dan ang ▁and ▁Cam ▁Ran h ▁Bay , ▁and ▁Soviet ▁reconna issance ▁aircraft ▁operated ▁out ▁of ▁Vietnam ese ▁air fields . ▁The ▁Vietnam ese ▁respond ed ▁to ▁the ▁Chinese ▁campaign ▁by ▁turning ▁the ▁districts ▁along ▁the ▁China ▁border ▁into ▁" ir on ▁for tr esses " ▁man ned ▁by ▁well - equ ipped ▁and ▁well - tra ined ▁par amil it ary ▁troops . ▁In ▁all , ▁an ▁estimated ▁ 6 0 0 , 0 0 0 ▁troops ▁were ▁assigned ▁to ▁counter ▁Chinese ▁operations ▁and ▁to ▁stand ▁ready ▁for ▁another ▁Chinese ▁invasion . ▁The ▁precise ▁dimensions ▁of ▁the ▁front ier ▁operations ▁were ▁difficult ▁to ▁determine , ▁but ▁its ▁mon et ary ▁cost ▁to ▁Vietnam ▁was ▁considerable . ▁ ▁By ▁ 1 9 8 7 , ▁China ▁had ▁station ed ▁nine ▁arm ies ▁( appro xim ately ▁ 4 0 0 , 0 0 0