Campaign 139
Campaign 139 was a major military offensive of the People's Army of Vietnam, launched against its Royalist enemies during the Laotian Civil War. Larger than previous invading forces, Campaign 139 was also a combined arms expedition containing tanks, artillery, engineers, and Dac Cong sappers. As such, it was a decided escalation in the war. It was also an exceptional rainy season offensive by PAVN, which usually withdrew during the wet season.
Launched on 14 September 1969 with 60 tanks, 26 PAVN and 10 Pathet Lao battalions, plus supporting units, Campaign 139 drove from the Lao/DRV border into the strategic Plain of Jars in Military Region 2 of the Kingdom of Laos. The 16,000 plus invaders were opposed by a force of Central Intelligence Agency sponsored hill tribes guerrillas some 5,500 to 6,000 strong. Hmong general Vang Pao's L'Armee Clandestine had just overrun the Plain during Kou Kiet, and the general elected to hold on. However, despite the best efforts of the guerrillas in a series of defensive clashes on and around the Plain, backed by massive air power, on 11 February 1970 the communists forced entrance to the Plain by capturing the crucial intersection of Routes 7/74. Having forced their way onto the Plain, the communists pushed their way across it to besiege the crucial main guerrilla base at Long Tieng. They overran the nearby refugee center at Sam Thong on 18 March 1970, and temporarily occupied the high ground overlooking the Lima Site 20A airstrip at Long Tieng used for resupplying the guerrillas. United States support of the irregulars was escalated, with the first B-52 Stratofortress Arc Light in northern Laos on 17 February, and the first ever use of the BLU-82 super-bomb on 22 March. On 18 March, irregular reinforcements were flown in from other military regions of Laos; so was a Royal Thai artillery battalion of mercenaries. Though the newly arrived guerrilla units were generally poor quality, they sufficed to fend off the exhausted PAVN. By 25 April 1970, the communists had fallen back onto their home ground near Dien Bien Phu, North Vietnam.
During the fighting, political negotiation between the Royal Lao Government and the Pathet Lao allies of the Vietnamese were attempted, to form a ceasefire agreement. Prime Minister Souvanna Phouma took advantage of his standing as a Neutralist to let it be privately known that Laos was willing to cease operations against the Ho Chi Minh Trail in southern Laos if the fighting was halted on the Plain. Hmong General Vang Pao quietly explored the option of moving his tribesmen and their guerrillas from the battlefield south to the Thai/Lao border. Campaign 139 ended with the Royalists scarcely able to defend the kingdom, which faced imminent defeat.
Overview
After World War II, France fought the First Indochina War to retain French Indochina. When it lost that war at Dien Ben Phu, it freed the Kingdom of Laos. Laotian neutrality was established in the 1954 Geneva Agreements. When France withdrew most of its military in conformity with the treaty, the United States filled the vacuum with purportedly civilian paramilitary instructors. A North Vietnamese-backed communist insurrection began as early as 1949. Invading during the opium harvest season of 1953, it settled in northeastern Laos adjacent to the border of the Democratic Republic of Vietnam.As the Laotian Civil War flared, it became apparent that the People's Army of Vietnam would be opposed by Lao guerrilla forces backed by air power. The Central Intelligence Agency established a secret guerrilla army in the Plain of Jars. Interposed between the communist settlement around Xam Neua and the Royal Lao Government in Vientiane, the Hmong military irregulars fought to hold on to their traditional territory, and to preserve Laos. After the failure and defeat of Operation Pigfat and Operation Raindance in early 1969, the communists had overrun the Plain of Jars to within ten kilometers of the guerrillas' main base at Long Chieng in Military Region 2. As a riposte, Hmong General Vang Pao had launched another spoiling offensive against the pressing communists with Kou Kiet. However, the communists fought back with their own campaign. Vang Pao had countered again, with Operation Off Balance.
Campaign 139 (1969-1970)
Campaign 139 was named by the Vietnamese communist military convention of encoding the founding date in an operational code name; in its case, the 13th day of the 9th month. On 13 September 1969, the Democratic Republic of Vietnam's General Võ Nguyên Giáp tasked General Vũ Lập with command of Campaign 139, to be waged in Military Region 2 of Laos. Included in the orders were ten Pathet Lao battalions for service; however, those battalions mustered only about 150 men each. Given their propensity for flight rather than fight, they were of dubious military value to Vũ Lập. The major forces in Campaign 139 would be the first PAVN combined arms team to invade northern Laos. Already in place in MR 2 awaiting Vũ Lập's leadership were 26 People's Army of Vietnam battalions and 60 tanks.Campaign 139
Phase one: the campaign begins
Campaign 139 kicked off the day after Vũ Lập received his orders. An advance party from the 141st Regiment of the 312th Division formed near Nong Het. Attacks upon Royalist irregulars at Phou Nok Kok followed, a fortnight later. On 25 October 1969, the communists committed a larger force for continuing the attack—the remainder of the 312th Division, the 316th Division, and the 866th Independent Regiment. Support units for these attacking forces came from four Dac Cong battalions, plus assorted artillery, engineer, and tank units. The 316th was directed to lead the support units down Route 7; the 312th Division and the 866th Independent Regiment were tasked for attack down Route 72. Within a week, the latter twice probed the Royalist positions at Phou Nok Kok, then continued to pressure them.On 6 November 1969, Vang Pao called a strategy session to revamp the Royalist irregulars' defenses. The success of his just concluded Kou Kiet had left him in possession of the strategic Plain of Jars, but with only 5,500 to 6,000 war-weary irregular troops to hold it. His Central Intelligence Agency advisers estimated he faced 16,000 North Vietnamese regulars, plus the Pathet Lao battalions. At such odds, they believed he had to go on the defensive. They had planned four successive lines of hilltop strongholds, with the idea that tactical air could destroy communists attacking the Royalist trenchworks. Even within each defensive line, the hilltop forts were not mutually reinforcing one another but were easily bypassed. Vang Pao was more realistic than his advisers; he still realized that guerrillas needed the tactical flexibility to fight or flee as circumstances demanded.
At the strategy meeting, he asked his CIA advisers for an extensive list of weaponry, and received more M16 rifles, and both 105mm and 155mm howitzers. He then outlined his plan to place blocking forces at both Xieng Khouangville and the intersection of Routes 7 and 71, with a reserve held at Lima Site 22. The latter was one of the few installations in Laos that had been developed into some approximation of a typical American fire support base in South Vietnam.
However, before these moves could be completed, the 165th Regiment of the PAVN 312th Division struck Xieng Khouangville on 9 November. The Royalist Bataillon Volantaire 24 repelled the assault. Upon a repeated attack on 17 November, BV 24 retreated. On the 23rd, Bataillon Infanterie 12 was returned home from Military Region 2 to Military Region 5.
Faced with these reverses, Vang Pao recalled Bataillon Volontaire 26 from its far northern outpost in Xam Neua, Houaphanh Province. Manning newly supplied 155 mm howitzers, and reinforced by PT-76 amphibious tanks captured from the communists, BV 26 retook Xieng Khouangville on 27 November 1969. While ordering this resistance, Vang Pao also stealthily contacted the Pathet Lao because he was anxious to preserve the Hmong people. He proposed that the communists grant autonomy to Xieng Khouang Province as a Hmong polity; in turn, the Hmong guerrillas would withdraw from the war. As an alternative move to preserve the Hmong, he also harbored the idea that the Hmong might withdraw to Sainyabuli Province near the Thai/Lao border.
Meanwhile, to the north of them, the communists probed Phou Nok Kok and Phou Pheung. The latter position was defended by a mix of Auto Defense Choc militia and Bataillon Volontaire 21, but had been weakened by the departure of BI 12. A battalion from the PAVN 141st Regiment cleared the Royalist garrison from the stronghold on 29 November; the monarchists retreated southward.
Also in late November, the Royalist battalion on Phou Nok Kok was relieved by a fresh unit. On 2 December, Dac Cong sappers bombarded the position with about 300 rounds of mortar fire, followed by a night assault using improvised Bangalore torpedoes. As the Royalists began to retreat at dawn, CIA case agent Wilbur "Will" Green, call sign "Black Lion", began calling in close air support, including 2,000 pound bombs. The strikes drove the communist sappers off the mountaintop.
A lull in communist activity followed, during which a melange of Royalist units launched a counterattack on 4 December. Hmong guerrillas manned PT-76 tanks captured from the communists, as well as 155 mm howitzers. They supported Bataillon Infanterie 19, as well as BV 21 and ADC militia. After recapturing Phou Pheung, they continued eastward to seize the Routes 71 and 74 junction.
By 12 December 1969, the guerrillas' CIA supporters realized that another PAVN drive was likely. They devised a plan for a strategic withdrawal in five phases in the face of overwhelming communist forces. However, guerrilla general Vang Pao turned down the withdrawal plan; he wanted to hold the Plain of Jars his forces had captured. He did pull in the ADC militia and their dependents from the last advanced guerrilla outpost at Houei Tong Ko near the Pathet Lao headquarters at Xam Neua.