Campaign Z
Part of Laotian Civil War; Vietnam War
​

​The Plain of Jars, the area in and around which Campaign Z was mainly fought,

Date: 17 December 1971 – 30 January 1972

Location:  Xiangkhouang Province

Result: People's Army of Vietnam fails to take Long Tieng
People's Army of Vietnam temporarily takes Skyline Ridge outside Long Tieng

Belligerents.     North Vietnam
​supported by:  Soviet Union, People's Republic of China,

                          Kingdom of Laos
Supported by
 United States
Thailand 
Commanders and leaders
Le Trong Tan. Vang Pao
Units involved
335th Independent Regiment
174th Regiment Mechanized Infantry
27th Sapper Battalion
195th Armored Battalion
312th Division
148th Regiment
14th Antiaircraft Battalion Groupement Mobile 21
Groupement Mobile 23
Groupement Mobile 22
Groupement Mobile 31
Groupement Mobile 30
Royalist guerrilla battalions

 Thai mercenary units including BC 609[1]Campaign Z (17 December 1971 – 30 January 1972) was a military offensive by the People's Army of Vietnam; it was a combined arms thrust designed to defeat the last Royal Lao Army troops defending the Kingdom of Laos. The Communist assault took Skyline Ridge overlooking the vital Royalist base of Long Tieng and forced the restationing of Royalist aviation assets and civilian refugees. However, Communist forces eventually receded back onto their lines of communication without capturing the base.
Campaign Z was notable for escalations of the Laotian Civil War conflict. The Vietnamese Communists brought 130 mm field guns and T-34 tanks into action in Laos for the first time. The Vietnamese People's Air Force also launched MiG 21 attacks into Lao air space to challenge the Royalist side's air supremacy. On its side, the Royal Lao Government and its Central Intelligence Agency backers imported copious numbers of mercenaries from the Kingdom of Thailand as reinforcements, and depended on American air power support, including Arc Light strikes by B-52 Stratofortresses. The Kingdom would narrowly survive Campaign Z.