7 ▁February ▁ 1 9 7 9 , ▁and ▁employed ▁inf antry , ▁arm or , ▁and ▁art illery . ▁Air ▁power ▁was ▁not ▁employed ▁then ▁or ▁at ▁any ▁time ▁during ▁the ▁war . ▁Within ▁a ▁day , ▁the ▁Chinese ▁People ' s ▁Liber ation ▁Army ▁( P LA ) ▁had ▁advanced ▁some ▁eight ▁kilom eters ▁into ▁Vietnam ▁along ▁a ▁broad ▁front . ▁It ▁then ▁slow ed ▁and ▁nearly ▁st alled ▁because ▁of ▁heavy ▁Vietnam ese ▁resistance ▁and ▁difficulties ▁within ▁the ▁Chinese ▁supply ▁system . ▁On ▁February ▁ 2 1 , ▁the ▁advance ▁res umed ▁against ▁C ao ▁Bang ▁in ▁the ▁far ▁north ▁and ▁against ▁the ▁all - important ▁regional ▁hub ▁of ▁Lang ▁Son . ▁Chinese ▁troops ▁entered ▁C ao ▁Bang ▁on ▁February ▁ 2 7 , ▁but ▁the ▁city ▁was ▁not ▁secured ▁completely ▁until ▁March ▁ 2 . ▁Lang ▁Son ▁fell ▁two ▁days ▁later . ▁On ▁March ▁ 5 , ▁the ▁Chinese , ▁saying ▁Vietnam ▁had ▁been ▁sufficiently ▁ch ast ised , ▁announced ▁that ▁the ▁campaign ▁was ▁over . ▁Be ij ing ▁declared ▁its ▁" less on " ▁finished ▁and ▁the ▁P LA ▁withdraw al ▁was ▁completed ▁on ▁March ▁ 1 6 . ▁ ▁H ano i ' s ▁post - inc urs ion ▁dep iction ▁of ▁the ▁border ▁war ▁was ▁that ▁Be ij ing ▁had ▁sust ained ▁a ▁military ▁set back ▁if ▁not ▁an ▁out right ▁defeat . ▁Most ▁obser vers ▁doubt ed ▁that ▁China ▁would ▁risk ▁another ▁war ▁with ▁Vietnam ▁in ▁the ▁near ▁future . ▁Ger ald ▁Seg al ,