Early history

Historically, Laos

Laos

Laos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...

 was subject to the will of its stronger neighbors

Southeast Asia

Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...

, enforced by military means. By force of circumstances in warding off repeated foreign invasions, Laotians developed battle skills using elephants

War elephant

A war elephant was an elephant trained and guided by humans for combat. Their main use was to charge the enemy, trampling them and breaking their ranks. A division of war elephants is known as elephantry....

 and compiled a history full of warlike deeds. Lan Xang

Lan Xang

The Lao kingdom of Lan Xang Hom Kao was established in 1354 by Fa Ngum.Exiled as an infant to Cambodia, Prince Fa Ngum of Xieng Dong Xieng Thong married a daughter of the Khmer king. In 1349 he set out from Angkor at the head of a 10,000-man army to establish his own country...

, or the Kingdom of the Million Elephants, the first state in the recorded history of Laos, maintained a standing army

Standing army

A standing army is a professional permanent army. It is composed of full-time career soldiers and is not disbanded during times of peace. It differs from army reserves, who are activated only during wars or natural disasters...

 of 150,000 men. Regiments included cavalry

Cavalry

Cavalry or horsemen were soldiers or warriors who fought mounted on horseback. Cavalry were historically the third oldest and the most mobile of the combat arms...

, infantry

Infantry

Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...

, and an elephant corps. Prince Fa Ngum

Fa Ngum

Somdetch Brhat-Anya Fa Ladhuraniya Sri Sadhana Kanayudha Maharaja Brhat Rajadharana Sri Chudhana Negara better known as Fa Ngum established the Lao kingdom of Lan Xang in 1354....

, Lan Xang's founder, redeveloped the old Mongol model

Mongol military tactics and organization

The Mongol military tactics and organization helped the Mongol Empire to conquer nearly all of continental Asia, the Middle East and parts of eastern Europe. In many ways, it can be regarded as the first "modern" military system....

 of an army composed of units of 10,000, which gave rise to the name of the successive reign, Sam Sen Tai, or, 10,000 Tai. The army's strength enabled Fa Ngum to expand Lan Xang's borders to the western escarpment of the Khorat Plateau

Khorat Plateau

The Khorat Plateau also Korat Plateau, is a plateau in the northeastern region of Thailand, named for the short form of Nakhon Ratchasima, an historical stronghold controlling access to and from the plateau.-Geography:...

, the crest of the Annamite Chain

Annamite Range

The Annamite Range or the Annamese Mountains is a mountain range of eastern Indochina, which extends approximately through Laos, Vietnam, and a small area in northeast Cambodia. It is known in Vietnamese as Dãy Trường Sơn, in Lao as Xai Phou Luang , and in French as the Chaîne Annamitique...

 in the east, and the northern edge of Khmer

Khmer Empire

The Khmer Empire was one of the most powerful empires in Southeast Asia. The empire, which grew out of the former kingdom of Chenla, at times ruled over and/or vassalized parts of modern-day Laos, Thailand, Vietnam, Burma, and Malaysia. Its greatest legacy is Angkor, the site of the capital city...

 and Cham civilizations in the south. To the north and east especially, however, mountain tribes resisted absorption and maintained a degree of independence.

Following Fa Ngum's death, struggles with Siamese

Thailand

Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

 and Burmese states in which his successors became embroiled, sapped the strength of the army and led to the decline and eventual splitting up of Lan Xang. In 1778 the capital of the Kingdom of Vientiane

Kingdom of Vientiane

Kingdom of Vientiane was formed in 1707 as a result of the split of the Kingdom of Lan Xang. The kingdom was a Burmese vassal . It then became a Siamese vassal until 1828 when it was annexed by Siam.-Kings:*Setthathirath II...

 was attacked and destroyed for the first time by a Siamese army. By the 1820s, Laos had reestablished sovereignty over its own borders, enough so that the king of Vientiane launched a disastrous military expedition against Siam (present-day Thailand). Laotian forces were overwhelmed by the superior firepower and strategy of the Siamese army, which attacked and destroyed Vientiane for a second time in 1828.

Colonial era

Following the destruction of Vientiane, Laotian affairs were dominated militarily by Siam, although the Vietnamese also involved themselves over the mountains (see Developments in the Nineteenth Century, ch. 1). It was not until 1884, when France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 guaranteed Annam the integrity of its territorial domain, that Siamese hegemony over the left bank of the Mekong

Mekong

The Mekong is a river that runs through China, Burma, Laos, Thailand, Cambodia and Vietnam. It is the world's 10th-longest river and the 7th-longest in Asia. Its estimated length is , and it drains an area of , discharging of water annually....

 encountered a new challenge. Using Annam's claims to Laotian territories as a diplomatic pretext, France forced Siam to renounce all claims to territory east of the Mekong and even to islands in the river by successive treaties between 1893 and 1907.

To preserve order in the new administrative structure and to reinforce their security forces, which up to the twentieth century consisted largely of Vietnamese militia, the French formed local Laotian police and military constabulary

Constabulary

Constabulary may have several definitions.*A civil, non-paramilitary force consisting of police officers called constables. This is the usual definition in Britain, in which all county police forces once bore the title...

 units and provided them with some modern weapons, equipment, and rudimentary training. The Laotian units, whose salaries were paid for by the royal house of Louangphrabang

Luang Prabang

Luang Prabang, or Louangphrabang , is a city located in north central Laos, where the Nam Khan river meets the Mekong River about north of Vientiane. It is the capital of Luang Prabang Province...

 (Luang Prabang), pledged allegiance to the monarchy, establishing a military tradition that ended only in 1975.

Between 1901 and 1907, France's colonial forces in Laos directed their attention to putting down a group of southern mountain Mon-Khmer

Khmer Loeu

The Khmer Loeu are the Mon–Khmer highland tribes in Cambodia. Although the origins of this group are not clear, some believe that the Mon–Khmer-speaking tribes were part of the long migration of these people from the northwest. The Austronesian-speaking groups, Rade and Jarai, apparently came to...

 rebels who had become angered over France's suppressing their customary slave-trading activities. Bandits from China's

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 Yunnan

Yunnan

Yunnan is a province of the People's Republic of China, located in the far southwest of the country spanning approximately and with a population of 45.7 million . The capital of the province is Kunming. The province borders Burma, Laos, and Vietnam.Yunnan is situated in a mountainous area, with...

 Province

Province

A province is a territorial unit, almost always an administrative division, within a country or state.-Etymology:The English word "province" is attested since about 1330 and derives from the 13th-century Old French "province," which itself comes from the Latin word "provincia," which referred to...

 also kept the colonial army occupied in the north between 1914 and 1916. The army's final major action—from 1919 to 1921—was against the Hmong

Hmong people

The Hmong , are an Asian ethnic group from the mountainous regions of China, Vietnam, Laos, and Thailand. Hmong are also one of the sub-groups of the Miao ethnicity in southern China...

 led by Pa Chay

Pa Chay Vue

Pa Chay Vue, , commonly referred to as Pa Chay or Batchai, led the Hmong people in the War of the Insane revolt against French rule in French Indochina from 1918 to 1921...

, who were conducting raids on the Lao and other groups in Houaphan and Xiangkhoang provinces with the aim of expelling the French and establishing an independent Hmong kingdom.

The first entirely Laotian military unit was formed by the French in 1941 and was known as the First Battalion of Chasseurs Laotiens (light infantry). It was used for internal security and did not see action until after the Japanese coup de force

Second French Indochina Campaign

The Second French Indochina Campaign, also known as the Japanese coup of March 1945, was a Japanese military operation in Cambodia, Laos and Vietnam, then a French colony and known as French Indochina, during the final months of the Second World War. Vietnam was not a real colony at this time. The...

 of March 9, 1945, when Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 occupied Laos. The unit then went into the mountains, supplied and commanded by Free French agents who had received special jungle training in camps in India and who had parachuted into Laos beginning in December 1944 with the aim of creating a resistance network.

Meanwhile, taking advantage of the temporary absence of French authority in the towns, the Lao Issara

Lao Issara

The Lao Issara was an anti-French, non-communist nationalist movement formed in 1945 by Prince Phetsarath. This short-lived movement emerged after the Japanese defeat in World War II and became the government of Laos before the return of the French. It aimed to prevent the French from restoring...

 government armed itself to defend the Laotian independence it claimed on behalf of the people. For the most part, effective components of the Lao Issara armed forces consisted of Vietnamese residents of the towns of Laos, who either had received weapons given them by the surrendering Japanese troops—sold by the Chinese Nationalist soldiers

National Revolutionary Army

The National Revolutionary Army , pre-1928 sometimes shortened to 革命軍 or Revolutionary Army and between 1928-1947 as 國軍 or National Army was the Military Arm of the Kuomintang from 1925 until 1947, as well as the national army of the Republic of China during the KMT's period of party rule...

 who occupied northern Laos under the 1945 Potsdam Conference

Potsdam Conference

The Potsdam Conference was held at Cecilienhof, the home of Crown Prince Wilhelm Hohenzollern, in Potsdam, occupied Germany, from 16 July to 2 August 1945. Participants were the Soviet Union, the United Kingdom, and the United States...

 agreements—or looted from French arsenals. In the Battle of Thakhek (Khammouan) in March 1946 that decided the issue of sovereignty in Laos in favor of the French, the Lao Issara used mortars and light machine guns against French armored vehicles and planes. One of the main preoccupations of the members of the Lao Issara government exiled in Bangkok

Bangkok

Bangkok is the capital and largest urban area city in Thailand. It is known in Thai as Krung Thep Maha Nakhon or simply Krung Thep , meaning "city of angels." The full name of Bangkok is Krung Thep Mahanakhon Amon Rattanakosin Mahintharayutthaya Mahadilok Phop Noppharat Ratchathani Burirom...

 between 1946 and 1949 was to procure weapons to fight back against the French.

French efforts to train and expand the Royal Lao Army continued during the First Indochina War

First Indochina War

The First Indochina War was fought in French Indochina from December 19, 1946, until August 1, 1954, between the French Union's French Far East...

 (1946–54), by which time Laos had a standing army of 15,000 troops. The French knew the lightly equipped Royal Lao Army

Royal Lao Army

The Royal Lao Army was the armed forces of the Kingdom of Laos. Its predecessor was the National Laotian Army - NLA of the French Union, created in 1947 from 'maquis', or guerrilla units gathered by French commandos. It was created in 1954 after the French granted Laos complete autonomy...

 was not in a position to defend Laos against Viet Minh

Viet Minh

Việt Minh was a national independence coalition formed at Pac Bo on May 19, 1941. The Việt Minh initially formed to seek independence for Vietnam from the French Empire. When the Japanese occupation began, the Việt Minh opposed Japan with support from the United States and the Republic of China...

 regular forces formed by General Vo Nguyen Giap

Vo Nguyen Giap

Võ Nguyên Giáp is a retired Vietnamese officer in the Vietnam People’s Army and a politician. He was a principal commander in two wars: the First Indochina War and the Vietnam War...

. To counter Viet Minh invasions of Laos in 1953 and 1954, the French Union High Command diverted regular colonial units from the Democratic Republic of Vietnam

North Vietnam

The Democratic Republic of Vietnam , was a communist state that ruled the northern half of Vietnam from 1954 until 1976 following the Geneva Conference and laid claim to all of Vietnam from 1945 to 1954 during the First Indochina War, during which they controlled pockets of territory throughout...

 into Laos; Giap exploited this weakness to disperse French Union forces. The French originally picked Dien Bien Phu

Dien Bien Phu

Điện Biên Phủ is a city in northwestern Vietnam. It is the capital of Dien Bien province, and is known for the events there during the First Indochina War, the Battle of Dien Bien Phu, during which the region was a breadbasket for the Việt Minh.-Population:...

 as the site of a major strong point because it blocked a main invasion route into Laos, which they felt they had to defend at all cost in order to preserve their credibility with the king of Louangphrabang, who sought France's protection. Some of the most effective fighters against the Viet Minh were Hmong from Xiangkhoang whom the French recruited and formed into guerrilla units; one of these units, under a sergeant named Vang Pao

Vang Pao

Vang Pao was a Lieutenant General in the Royal Lao Army. He was an ethnic Hmong and a leader of the Hmong American community in the United States.-Early life:...

, was on the march to Dien Bien Phu when the garrison fell in May 1954.

Under the terms of the armistice signed at the Geneva Conference on Indochina

Geneva Conference (1954)

The Geneva Conference was a conference which took place in Geneva, Switzerland, whose purpose was to attempt to find a way to unify Korea and discuss the possibility of restoring peace in Indochina...

 on July 20, 1954, by the French Union High Command and the Viet Minh, all Viet Minh troops had to withdraw from Laos within 120 days. Laos was prohibited from having foreign military bases or personnel on its soil and from joining any military alliance. The agreements provided for the regrouping of Pathet Lao

Pathet Lao

The Pathet Lao was a communist political movement and organization in Laos, formed in the mid-20th century. The group was ultimately successful in assuming political power after the Laotian Civil War. The Pathet Lao were always closely associated with Vietnamese communists...

 guerrillas

Guerrilla warfare

Guerrilla warfare is a form of irregular warfare and refers to conflicts in which a small group of combatants including, but not limited to, armed civilians use military tactics, such as ambushes, sabotage, raids, the element of surprise, and extraordinary mobility to harass a larger and...

 in the provinces of Houaphan and Phôngsali

Phongsali

Phongsali or Phongsaly is the capital of Phongsali Province, Laos. It is the northernmost among provincial capitals in Laos opposite Attapeu in the south. The town has about 6,000 inhabitants and is located at approximately 1430 meters on the slopes of Mount Phu Fa . Phongsali has pleasant summer...

 and their integration into the Royal Lao Army. The Pathet Lao, however, taking advantage of their easy access across the border to North Vietnam, immediately began to expand their guerrilla army, the first unit of which, the Latsavong detachment, had been formed in 1949 by Kaysone Phomvihane

Kaysone Phomvihane

Kaysone Phomvihane was the leader of the Lao People's Revolutionary Party from 1955, though Souphanouvong served in a figurehead role...

.

Royal Lao Army

With the end of the war, Laos was no longer under the French Union but entirely sovereign. The country was divided into five military regions. The chain of command of the Royal Lao Army was placed under the Ministry of Defense in Vientiane.

To meet the threat represented by the Pathet Lao, the Royal Lao Army depended on a small French military training mission, headed by a general officer, an exceptional arrangement permitted under the Geneva agreement. Military organization and tactical training reflected French traditions. Most of the equipment was of United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 origin, however, because early in the First Indochina War, the United States had been supplying the French with matériel

Materiel

Materiel is a term used in English to refer to the equipment and supplies in military and commercial supply chain management....

 ranging from guns to aircraft. A small United States legation in Vientiane kept Washington informed about the status of the Royal Lao Army. There was real concern that Laotians were not maintaining their equipment properly and that much of it was becoming useless under the tropical sun and rain. The question also arose of who was to pay the salaries of the Royal Lao Army as France was no longer responsible for Laos's finances.

It seemed evident to the legation that only United States personnel in Laos could ensure that the Royal Lao Army was capable of meeting the threat posed by the Pathet Lao backed by North Vietnam. To get around the prohibition against foreign military personnel imposed by the 1954 Geneva agreement—which the United States had pledged to honor—the Department of Defense

United States Department of Defense

The United States Department of Defense is the U.S...

 in December 1955 established a disguised military mission in Laos called the Programs Evaluation Office

Programs Evaluation Office

The Programs Evaluation Office was a military mission to Laos, established in 1955 by the United States Department of Defense.-Motive:With the end of World War II, Laos was no longer under the French Union but entirely sovereign and was governed by the Royal Lao Government. The Royal Lao Army was...

 (PEO). The PEO worked under the cover of the civilian aid mission and was staffed by military personnel and headed by a general officer who wore civilian clothes. Over the 1955-61 period, the PEO gradually supplanted the French military mission in providing equipment and training to the Royal Lao Army. With increasing numbers of Laotian officers receiving training in Thailand and at staff schools in the United States, there was a perception that the French military mission in Laos was a relic of colonialism

Colonialism

Colonialism is the establishment, maintenance, acquisition and expansion of colonies in one territory by people from another territory. It is a process whereby the metropole claims sovereignty over the colony and the social structure, government, and economics of the colony are changed by...

. By 1959 the PEO had more than 100 members on its staff, and the United States was paying the entire cost of the Royal Lao Army's salaries.

The prohibition against joining any military alliance prevented Laos from joining the Southeast Asia Treaty Organization

Southeast Asia Treaty Organization

The Southeast Asia Treaty Organization was an international organization for collective defense in Southeast Asia created by the Southeast Asia Collective Defense Treaty, or Manila Pact, signed in September 1954 in Manila, Philippines. The formal institution of SEATO was established on 19 February...

 (SEATO), formed by Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, Britain

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

, Pakistan

Pakistan

Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...

, the Philippines

Philippines

The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

, Thailand

Thailand

Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

, and the United States in September 1954. However, a protocol to the treaty designated Laos as a country to which its mutual security provisions would apply in the event it became the victim of aggression. When fighting broke out along Laos's border with North Vietnam in July–September 1959 following the collapse of efforts to integrate two battalions of Pathet Lao into the Royal Lao Army, the Royal Lao Government

Royal Lao Government

The Royal Lao Government was the ruling authority in the Kingdom of Laos from 1947 until the communist seizure of power in December 1975 and the proclamation of the Lao People's Democratic Republic...

(RLG) wanted to appeal to SEATO for help. The RLG was dissuaded from doing so by the United States, which felt that such an appeal risked involving United States troops in combat in Laos. The nature of the fighting—by guerrillas belonging to ethnic tribes that lived on both sides of the border—made the question of aggression ambiguous. Similarly, in January 1961, when the RLG proposed appealing to SEATO to counter North Vietnam's intervention on behalf of the Pathet Lao and Kong Le

Kong Le

Kong Le is a former paratrooper captain in the Royal Lao Army known for overthrowing the government of Laos in a 1960 coup d'état. He obtained his training from the Armed Forces of the Philippines in 1957 and joined the Royal Lao Army in 1960.-Coup of 1960:...

, it was discouraged from doing so by the United States.

Kong Le's coup d'état

Kong Le

Kong Le is a former paratrooper captain in the Royal Lao Army known for overthrowing the government of Laos in a 1960 coup d'état. He obtained his training from the Armed Forces of the Philippines in 1957 and joined the Royal Lao Army in 1960.-Coup of 1960:...

 on August 9, 1960, threatened to split the army between Kong Le's Lao Neutralist Revolutionary Organization--known as the Neutralists, whose troops' unofficial name was the Neutralists Armed Forces—and the rest of the army under General Phoumi Nosavan

Phoumi Nosavan

Phoumi Nosavan was a Lao military and political figure of the Vietnam War . Nosavan was of Chinese descent....

, the former minister of defense. PEO headquarters in Vientiane became inactive because United States diplomats were instructed to find a way to isolate the rebellious paratrooper. Finally, aid was cut off. Meanwhile, the PEO branch office in Savannakhet

Savannakhet

Savannakhet or Kaysone Phomvihane is a city in western Laos and the capital of the Savannakhet Province, previously known as Khanthabouli . This is the second-largest city in Laos, after Vientiane. The city is birthtown of Kaysone Phomvihane, former president of Laos, and was named after him in...

--Phoumi's headquarters—continued to supply and pay Phoumi's troops. After Phoumi captured Vientiane, the Neutralists were compelled—for their survival—to enter into an alliance with the Pathet Lao and their North Vietnamese backers, on whom they thereafter depended for supplies.

In April 1961, the PEO was upgraded to a Military Assistance Advisory Group

Military Assistance Advisory Group

Military Assistance Advisory Group is a designation for American military advisers sent to assist in the training of conventional armed forces of Third World countries. Before and during the Vietnam War, there were three of these groups operating in Southeast Asia...

 (MAAG), and its members were allowed to wear uniforms. The MAAG was withdrawn in 1962 under the terms of the Geneva Agreement, which was supposed to neutralize Laos. Because the North Vietnamese did not respect the withdrawal requirement the United States stepped up military aid to the RLG, but avoided sending ground troops into Laos which would have violated the agreement.

As part of this effort, United States Central Intelligence Agency

Central Intelligence Agency

The Central Intelligence Agency is a civilian intelligence agency of the United States government. It is an executive agency and reports directly to the Director of National Intelligence, responsible for providing national security intelligence assessment to senior United States policymakers...

 (CIA) personnel operating from a base at Udon Thani

Udon Thani

Udon Thani is a city in Isan, north-east Thailand, and the capital of Udon Thani Province.-Location:The province of Udon Thani has a population of 1,467.200, the city alone 500.000. Geographical location and is approximately 560 km from Bangkok...

, Thailand, took over the support of 30,000- to 36,000-person irregulars, including Hmong guerrillas who bore the brunt of the fighting in northern Laos. A CIA-chartered airline, Air America, dropped rice and ammunition from its C-46s and C-47s to isolated Hmong outposts, which were sometimes behind enemy lines. A variety of short takeoff and landing aircraft used dirt airstrips carved out of the jungle by the Hmong. The irregulars, who became known as the Secret Army, were instrumental in helping to rescue a large number of United States airmen who were shot down over Laos. By this time, the Hmong leader Vang Pao had risen to the rank of general in the Royal Lao Army and commanded the Second Military Region.

In October 1964, in response to an offensive by the Pathet Lao and North Vietnamese to expel the Neutralists from the Plain of Jars

Plain of Jars

The Plain of Jars is a megalithic archaeological landscape in Laos. Scattered in the landscape of the Xieng Khouang plateau Xieng Khouang, Lao PDR, are thousands of megalithic jars...

, the United States began providing air support against Pathet Lao positions and North Vietnamese supply lines. However, it was not until March 1966 at Phoukout, northwest of the Plain of Jars, that the Pathet Lao started to win major battles against the Royal Lao Army. In July 1966, the Pathet Lao won another major battle in the Nambak Valley in northern Louangphrabang Province by overrunning a Royal Lao Army base and inflicting heavy casualties. These victories gave the Pathet Lao new momentum in the war for control of Laos.

Meanwhile, in southern Laos, where the North Vietnamese had been working steadily every dry season to expand the Ho Chi Minh Trail

Ho Chi Minh trail

The Ho Chi Minh trail was a logistical system that ran from the Democratic Republic of Vietnam to the Republic of Vietnam through the neighboring kingdoms of Laos and Cambodia...

 network leading into the Republic of Vietnam

South Vietnam

South Vietnam was a state which governed southern Vietnam until 1975. It received international recognition in 1950 as the "State of Vietnam" and later as the "Republic of Vietnam" . Its capital was Saigon...

 (South Vietnam), the intensity of the air war also grew. The air war in Laos operated under a complicated command and control system that involved the United States embassy in Vientiane, the Military Assistance Command Vietnam in Saigon, Royal Thai air bases in Thailand, the commander in chief Pacific in Honolulu, and sometimes even the White House

White House

The White House is the official residence and principal workplace of the president of the United States. Located at 1600 Pennsylvania Avenue NW in Washington, D.C., the house was designed by Irish-born James Hoban, and built between 1792 and 1800 of white-painted Aquia sandstone in the Neoclassical...

. The United States ambassador in Vientiane had the final say on target selection, using criteria that included taking into account the distance of targets from civilian habitations and the types of ordnance to be expended. The ambassador also was to keep the RLG informed so as to avoid, or at least minimize, the latter's embarrassment vis-à-vis the British and Soviet embassies in Vientiane and the heads of the Indian, Canadian, and Polish delegations to the International Control Commission

International Control Commission

The International Control Commission , formally called the International Commission for Supervision and Control in Vietnam , was an international force established in 1954 that oversaw the implementation of the Geneva Accords that ended the First Indochina War with the Partition of Vietnam. It...

 who were jointly responsible for enforcing the 1962 Declaration on the Neutrality of Laos signed in Geneva.

During the June 1969 rainy season, the Pathet Lao and two North Vietnamese battalions, using Soviet tanks, pushed the Royal Lao Army and the Neutralists out of their base at Muang Sua

Muang Sua

Muang Sua was the name of Luang Phrabang following its conquest in 698 by a Tai prince, Khun Lo, who seized his opportunity when the king of Nanzhao was engaged elsewhere. Khun Lo had been awarded the town by his father, Khun Borom, who is associated with the Lao legend of the creation of the...

 northwest of the Plain of Jars. Fighting continued during the monsoon

Monsoon

Monsoon is traditionally defined as a seasonal reversing wind accompanied by corresponding changes in precipitation, but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea...

 season. In September 1969, Vang Pao's Hmong, supported by United States bombing, launched a series of surprise attacks against key points on the Plain of Jars. A new North Vietnamese army division joined the battle shortly thereafter and by February 1970 had regained all of the devastated plain.

In 1970, despite eight years of ground offensives by the Royal Lao Army and massive United States air support, the Pathet Lao had grown into an army of 48,000 troops and was prepared to challenge Royal Lao Army forces on their own territory by mounting large offensives in the south engaging an even greater number of North Vietnamese forces. The introduction of Soviet-made long-range 130- mm artillery pieces onto the battlefield in that year allowed the Pathet Lao and North Vietnamese to neutralize to some extent the Royal Lao Army's advantage of air superiority.

In 1970 the combat elements of the Royal Lao Army were organized into fifty-eight infantry battalions and one artillery regiment of four battalions. The largest tactical unit was the battalion, which was composed of a headquarters, a headquarters company, and three rifle companies. Royal Lao Army units were devoted primarily to static defense and were stationed near population centers, lines of communication, depots, and airfields. These units were complemented by military police and armored, engineer, and communications units. Between 1962 and 1971, the United States provided Laos with an estimated US$500 million in military assistance, not including the cost of equipping and training irregular and paramilitary forces. During the 1971-75 period, it added about seventy-five T-28 light-strike or training aircraft, about twenty C-47s in both transport and gunship configurations, fewer than ten H-34 helicopters, and some small U-1 and U-17 aircraft.

In February 1971, a major offensive by the South Vietnamese army, with United States logistical and air support, sent two divisions into Laos in the vicinity of Xépôn with the objective of cutting North Vietnamese supply lines. However, once inside Laos, South Vietnamese commanders were separated from their resupply bases by long logistics lines resulting in an early termination of the offensive. By December 1971, the Pathet Lao had taken Paksong on the Bolaven Plateau

Bolaven Plateau

The Bolaven Plateau is an elevated region in Laos. It is located between the Annamite Mountain Range, along which runs Laos’ eastern border with Vietnam, and the Mekong River to the west, at about . The plateau's elevation ranges approximately from above sea level. The plateau is crossed by...

and had invested the main Hmong base at Longtiang. Communist advances continued into 1972 and encircled Thakhek on the Mekong, and Vientiane.

The cease-fire of February 22, 1973, ended United States bombing and temporarily halted ground offensives. The Pathet Lao, however, following their usual practice, used the cessation of military operations to resupply their forces over the long and exposed roads from North Vietnam. In further fighting in the spring of 1975, the Pathet Lao finally broke the resistance of Vang Pao's Hmong blocking the road junction linking Vientiane, Louangphrabang, and the Plain of Jars. Under the watch of two battalions of Pathet Lao troops, which had been flown into Vientiane and Louangphrabang on Soviet and Chinese planes for neutralizing those towns under the cease-fire agreement, the communists organized demonstrations to support their political and military demands, leading to the final, bloodless seizure of power in the towns that the RLG had held up to then.