The PAVN short sharp riposte of Campaign Toan Thang during 18–27 June 1969 redressed the balance by capturing the strategic forward air base at Muang Soui.
At its end, the Vietnamese Communists had conquered the Plain and besieged the main guerrilla base at Long Tieng, nearly winning the war.
The aptly named Operation Counterpunch by the Royalists, fought during Autumn 1970, succeeded in buying the Hmong some time.
Their CIA supporters arranged for reinforcement by Thai mercenary battalions from Operation Unity, as little manpower was available from other military regions.
[7][8][9] Meantime, the PAVN moved T-34 tanks and 16 130mm field guns from North Vietnam into Laos to support future offensives.
[10][11] The annual Hmong New Year kicked off on 16 December 1971; many officers found their way rearward from their front-line units to the celebration.
[13] Simultaneously, the 312th PAVN Division retraced its previous successful line of attack, driving down Route 72 at Groupement Mobile 22 in the southeastern PDJ.
Anticipating the PAVN arrival, the guerrillas began to abandon their weapons as they sifted to the rear past the Thai fire bases.
[14][15] Combat Search and Rescue (CSAR) for the downed fliers on 19 December absorbed fifty aircraft in its efforts, leading to another day of weak tactical air support for the Royalists.
Even after the end of the CSAR, air support was weakened by necessary countermeasures to MiG 21 intrusions, whether real or feinted.
[18][19][20] On 30 December 1971, Communist forces attacked Sala Phou Khoun, a strategic intersection in the Royalist rear; the counter for this would become Operation Maharat.
Given the gravity of the PAVN threat to the Long Tieng base, its aviation operations were dispersed away from Communist reach.
On 11 January, CIA case agents began construction of hardened bunkers for protection from shell fire.
They pushed a Thai mercenary battalion from the Charlie Alpha helicopter landing zone, the highest point on Skyline Ridge overlooking Long Tieng.
Meanwhile, down south in Bangkok, the deputy chairman of the National Executive Council floated the idea that the Hmong could relocate to Thailand to escape the war.
[25] On 12 January, GM 30 was lifted back to the base of Skyline Ridge and ascended to the Charlie Echo landing pad on its western end.
The subsequent eastward assault along the ridgeline on 17 January by GM 30 was supported by the Thais, artillery fire, and B-52 strikes.
[26] On 14 January, the PAVN's daily newspaper, Quan Doi Nhan Dan, proclaimed victory at Long Tieng.
Previously denied access to the secretive base at Long Tieng, on 19 January the journalists were finally granted entry.
After their retreat, their position was occupied by a Royalist guerrilla battalion advised by CIA case agent George Bacon, call sign Kayak.
By then, four supporting Thai artillery positions had been set up in an arc about nine kilometers south of Long Tieng.
[29] As in Campaign 139, the PAVN pulled up just short of overrunning Long Tieng and ending the Laotian Civil War.
On the other hand, removing the Hmong from their traditional homeland might irretrievably break their fighting spirit, and lose the war.
However, Ambassador G. McMurtrie Godley, who actually directed the war, believed that with the PAVN being attrited by air strikes, the Hmong could endure.