Other countries' involvement
The Soviet Union supplied North Vietnam with medical supplies, arms, tanks, planes, helicopters, artillery, ground-air missiles and other military equipment. Hundreds of military advisors were sent to train the Vietnamese army. Soviet pilots acted as a training cadre and many flew combat missions as "volunteers".[citations needed] Fewer than a dozen Soviet citizens lost their lives in this conflict. After the war, Moscow became Hanoi's main ally.
China's involvement in the Vietnam War began in 1949, when the communists took over the country. The Communist Party of China (CPC) provided material and technical support to the Vietnamese communists. In the summer of 1962, Mao Zedong agreed to supply Hanoi with 90,000 rifles and guns free of charge. After the launch of Operation Rolling Thunder, China sent anti-aircraft units and engineering battalions to North Vietnam to repair the damage caused by American bombing, rebuild roads, railroads and to perform other engineering works. This freed North Vietnamese army units for combat in the South. Between 1965 and 1970 over 320,000 Chinese soldiers served in North Vietnam. The peak was 1967, when 170,000 served there. Although Chinese assistance was accepted gladly, the North Vietnamese remained distrustful of their larger neighbour. This was due to the historical antipathy between the two nations. China emerged as the principle backer of the Khmer Rouge. The People's Republic of China briefly launched an invasion of Vietnam in 1979, in retaliation for its invasion of Cambodia to depose the Khmer Rouge. In April 2006, a ceremony was held in Vietnam to honor the almost 1100 Chinese soldiers who were killed in the Vietnam War.
As a result of a decision of the Korean Workers' Party in October 1966, in early 1967, North Korea sent a fighter squadron to North Vietnam to back up the North Vietnamese 921st and 923rd fighter squadrons defending Hanoi. They stayed through 1968, and 200 pilots were reported to have served. In addition, at least two anti-aircraft artillery regiments were sent as well. North Korea also sent weapons, ammunition and two million sets of uniforms to their comrades in North Vietnam. Kim Il Sung is reported to have told his pilots to "fight in the war as if the Vietnamese sky were their own".
The South Korea had the second-largest contingent of foreign troops in South Vietnam after the United States. South Korea dispatched its first troops in 1964. Large combat battalions began arriving a year later. South Korean troops developed a reputation for ruthlessness. Approximately 320,000 South Korean soldiers were sent to Vietnam. As with the United States, soldiers served one year. The maximum number of South Korean troops peaked at 50,000. More than 5,000 South Koreans were killed and 11,000 were injured in the war. All troops were withdrawn in 1973.
Some 1,450 troops were dispatched to South Vietnam. They were primarily engaged in medical and other civilian pacification projects. These forces operated under the designation PHLCAAG or Philippines Civil Affairs Assistance Group.
Australia and New Zealand
As U.S. allies under the ANZUS Treaty, Australia and New Zealand sent ground troops to Vietnam. Both nations had gained valuable experience in counterinsurgency and jungle warfare during the Malayan Emergency. Geographically close to Asia, they subscribed to the Domino Theory of communist expansion and felt that their national security would be threatened if communism spread further in Southeast Asia. Australia's peak commitment was 7,672 combat troops, New Zealand's 552 and most of these soldiers served in the 1st Australian Task Force which was based in Phuoc Tuy Province. Australia re-introduced conscription to expand its army in the face of significant public opposition to the war. Like the U.S., Australia began by sending advisers to Vietnam, the number of which rose steadily until 1965, when combat troops were committed. New Zealand began by sending a detachment of engineers and an artillery battery, and then started sending Special Forces and regular infantry. Several Australian and New Zealand units were awarded U.S. unit citations for their service in South Vietnam. The ANZUS forces were cohesive and well-disclipined.
Thai Army formations, including the "Queen's Cobra" battalion saw action in South Vietnam between 1965 and 1971. Thai forces saw much more action in the covert war in Laos between 1964 and 1972. There, Thai regular formations were heavily outnumbered by the irregular "volunteers" of the CIA-sponsored Police Aerial Reconnaissance Units or PARU, who carried out reconnaissance activities on the western side of the Ho Chi Minh Trail. The activities of these personnel remain one of the great unknown stories of the South East Asian conflict.
Canadian, Indian and Polish troops formed the International Control Commission, which was supposed to monitor the 1954 ceasefire agreement. The Canadian government also lent diplomatic assistance to the United States to establish contact with the North Vietnamese regime. The government of Prime Minister Lester B. Pearson resisted considerable U.S. pressure to send troops to Vietnam. Although not a major arms supplier, Canadian-made military hardware was used in Vietnam, including large amounts of Agent Orange manufactured by Dow Chemical. Most Canadians who served in the Vietnam War were members of the United States military with estimated numbers ranging from 2,500 to 12,000. Many became U.S. citizens upon returning from Vietnam or were dual citizens prior to joining the military. The Canadian government gave political asylum to significant numbers of American deserters and draft dodgers during the conflict. Canada hosted 30,000–90,000 Americans seeking asylum. A large number returned to the United States after a pardon was issued by President Jimmy Carter. The remainder, roughly half, chose to stay in Canada.