1 9 7 2 , ▁Royal ist ▁def enses ▁in ▁southern ▁La os ' ▁pan handle ▁had ▁been ▁be aten ▁back ▁until ▁some ▁Commun ist ▁troops ▁had ▁pushed ▁to ▁the ▁M ek ong ▁River ▁border ▁between ▁La os ▁and ▁Th ailand . ▁Unity ▁troops ▁were ▁being ▁shift ed ▁between ▁Military ▁Reg ions ▁ 2 ▁and ▁ 4 ▁to ▁f end ▁off ▁increasing ▁P AV N ▁might . ▁The ▁Royal ist ▁Black ▁Lion ▁off ens ives — Oper ations ▁Black ▁Lion , ▁Black ▁Lion ▁III , ▁and ▁Black ▁Lion ▁V — w ere ▁w aged ▁from ▁ 1 5 ▁June ▁ 1 9 7 2 ▁through ▁ 2 2 ▁February ▁ 1 9 7 3 ▁in ▁a ▁vain ▁attempt ▁to ▁st ave ▁off ▁defeat . ▁The ▁Th ai ▁mer cen aries ▁made ▁up ▁most ▁of ▁the ▁Royal ist ▁fighting ▁force . ▁ ▁Military ▁Region ▁ 2 ▁ ▁The ▁Royal ists ▁faced ▁many ▁difficulties ▁in ▁Military ▁Region ▁ 2 . ▁Fire ▁Support ▁Base ▁P unch er , ▁the ▁Ban ▁Na ▁out post ▁of ▁Long ▁T ien g , ▁was ▁surrounded ▁by ▁P AV N ▁inf antry ▁and ▁sa ppers . ▁On ▁ 1 4 ▁February ▁ 1 9 7 1 , ▁an ▁accident al ▁bomb ing ▁killed ▁ 3 0 ▁civ ili ans . ▁By ▁ 1 5 ▁February , ▁V ang ▁Pa o ' s ▁L ' Ar mee ▁C land est ine ▁was ▁in ▁des perate ▁shape . ▁The ▁P AV N ▁were ▁within ▁striking ▁distance ▁of ▁the ▁main ▁gu err illa ▁base