Australia mirrored the US. We sent in US Advisors and Special Forces (Green Beret), the Australians did the same (with their equivalent). When the US escalated, the Australians escalated.
The North Vietnam Army (NVA) and the United States.(with help from Australia and minimal help from South Vietnam)
Both were members of the South East Asia Treaty Organization (SEATO) - as was the Republic of South Vietnam.
In 1961 and in 1962, Ngo Dinh Diem, leader of the government in South Vietnam, repeatedly asked for assistance from America and its allies to help its security. Australia eventually accepted and sent 30 military advisers from the Australian Army Training Team to Vietnam. These advisors were experts in jungle warfare and helped the US and South Vietnamese troops significantly. By 1965 it was obvious that South Vietnam could not beat the communists, so America sent over 200,000 more troops and requested more support from its allies (Australia).
North Vietnam invaded South Vietnam. Russia and China and to a smaller extent Cuba came alongside North Vietnam to help their cause. The United States, Canada, Australia, Philippines, and Korea aided South Vietnam in defending their sovereignty.
Australia sent Warships (Destroyers); Infantrymen and Centurion tanks to Vietnam.
North Vietnam was supported by Soviet Union money and military equipment. Help also came from China, and later from Cuba. South Vietnam, as a member of the South East Asia Treaty Organization (SEATO), was supported by the United States, Canada, South Korea, Australia, and the Philippines.
US, Australia, New Zealand, Philippines, Thailand, South Korea (ROK), all helped.
Somewhat democratic South Vietnam was a member of the South East Asia Treaty Organization (SEATO), so by treaty, we were obligated to help defend South Vietnam. We entered the Vietnam War to help South Vietnam stop Communist North Vietnam from their attempts to unify the whole country.
The Vietnam War (1955-1975) was primarily fought between South Vietnam (ARVN) and the United States versus North Vietnam (NVA) and the Viet Cong. South Vietnam and the U.S. also had help from Australia, South Korea, and others, while the NVA and the Viet Cong had materiel support from the Soviet Union and the People's Republic of China.
South Vietnam NEEDED help each year. The problem NEVER got better. It just grew and grew.
?........the Vietnam war was a war between north and south Vietnam and America. America was trying to defend south Vietnam from the north invading and controling their territory. so America was on the side with south Vietnam
Defending South Vietnam against Communist aggression from North Vietnam.