Warmatrix

The Vietnam War, also called the second Indochina War, was one of the largest conflicts of the Cold War. It lasted two decades, raged over half of southeast of Asia and inflicted a humiliating defeat on the USA.
After the First Indochina War, ending with Battle of Dien Bien Phu in 1954 CE, France, which had ruled Vietnam, Cambodia and Laos as its Indochina colony for almost a century, pulled out of southeast Asia. Vietnam was temporarily divided into two halves. North Vietnam was more rural and sympathetic to the communists, while the south was more cosmopolitan and leaned towards capitalism. Country-wide elections had to re-unite the country, yet never took place.
In 1955 CE the autocratic Ngo Dinh Diem proclaimed himself president of South Vietnam. His nepotism increasingly alienated the population in the countryside, while infiltrators from the north stirred more dissent. Poor leadership and corruption prevented the South Vietnamese Army to effectively quell the insurgency. This effectively was the start of the war, though it was small scale at first.
Throughout the war, the USSR and China supported North Vietnam and the Viet Cong with financial aid, food, engineers, training and weapons. The USA, which followed a doctrine of fighting communism all over the world, supported the south, initially with with military advisors and money. Several other countries lent small support to either the north or the south. In 1963 Diem was assassinated by some generals and the south Vietnamese government became very unstable, coup following coup. In response the new American president Johnson abused a naval incident in the Gulf of Tonkin to gain support for sending troops to Vietnam. Both sides stepped up their involvement. The number of American troops rose from 2,000 in 1961 CE to 23,000 in 1964 CE. The strength of the Viet Cong, the guerrilla army in the south, rose from 5,000 in early 1959 CE to 100,000 near the end of 1964 CE. It was organized in layers ranging from part-time guerrillas to full time soldiers.
At the Battle of Binh Gia in late 1964 CE the Viet Cong, which had been limited to guerrilla hit-and-run attacks before, defeated the South Vietnamese Army for the first time in an open battle. At that point the war really escalated. The USA reacted by starting several bombing campaigns on North Vietnam and the 'Ho Chi Minh Trail' supply route, which also ran through Laos and Cambodia. It also sent in US marines as a ground force, reaching a strength of 200,000 troops by the end of 1965 CE and 535,000 in April 1969 CE, though never formally declared war. These troops defeated the communist forces in several battles, but could not break them, as the latter simply retreated to the jungles and mountains, where they resorted back to guerrilla warfare.
The USA and South Vietnamese army extensively used transport helicopters to rapidly redeploy troops and attack helicopters as flying artillery. They had a clear advantage in firepower, from artillery, heavy tanks and especially aircraft. Bombers dropped 7 million tons of bombs, most on Viet Cong forces in South Vietnam, but also North Vietnam and Cambodia. Defoliants like Agent Orange caused considerable damage to the forests and killed people too. The effects of the poisons in them lingered on for decades. The American strategy was one of attrition, which proved ineffective. During the war North Vietnam strengthened its air defenses, which took a rising toll on American aircraft. The North Vietnamese and Viet Cong troops were numerous and determined; they persevered. Veterans brought experience from the First Indochina War and younger soldiers were quickly bloodied too. In contrast, all American troops served a tour duty of one year, preventing a buildup of experience.
In early 1968 CE the North Vietnamese Army and the Viet Cong, in attempt to wage conventional war again, launched a surprise offensive during the Tet festival, attacking more than 100 cities with 85,000 troops and even penetrating into the US embassy in Saigon. After the initial shock, the South Vietnamese and American forces struck back and beat off the offensive, though the historical capital of Hue was shot to pieces in the process. The Tet offensive was a military defeat for the communists, who suffered heavy losses, but turned out a political victory for them. During the war, the American government had painted a much more optimistic picture of the war than independent journalists had done, who were painfully proven right by the Tet offensive. A year later Johnson was forced to start peace talks with North Vietnam and soon after lost his presidency to Richard Nixon. The latter, faced with increasing opposition to the war, which was fueled by exposure of several war crimes by American soldiers, started to withdraw American forces. He adopted a policy of 'Vietnamization', i.e. training and equipping the South Vietnamese Army so that it could handle the war on its own.
In the meanwhile the fighting spilled over into Laos, invaded by North Vietnam as early as 1955 CE, and neutral Cambodia, where American bombers and South Vietnamese ground troops tried to cut the Ho Chi Minh trail. North Vietnam counter-invaded Cambodia in 1970 CE and launched another offensive against South Vietnam two years later. American airpower held it at bay in Operation Linebacker I. A peace agreement was reached but broke apart before it could be implemented. In response the USA bombed a large part of North Vietnam's industry to rubble in Operation Linebacker II. Meanwhile in the south the withdrawal continued; the the last American ground troops left Vietnam in 1973 CE. They two Linebacker bombing campaigns were much heavier than those of the early years of the war. They brought North Vietnam back to the negotiation table, where a peace treaty was signed.
However the treaty was violated by both sides from the start. South Vietnam launched an offensive of its own, but was driven back within a year. In 1975 CE, with improved routes and sensing that the USA would not interfere again, North Vietnam launched its final offensive against the south. The South Vietnamese army had a 3:1 advantage in artillery, 2:1 in infantry, tanks and aircraft, though suffered from a shortage of fuel. But the northern troops were more determined and steadily drove them back. Before the summer, they secured a final victory. The USA had tried to win the war by attrition; instead they were beaten by it. More importantly, they mostly tried to win by military means while they should have helped the Vietnamese more to build a nation, though that ultimately was the responsibility of the Vietnamese themselves.
In the war the USA sustained 210,000 casualties, including 60,000 deaths and the South Vietnamese Army around 1,400,000, including 230,000 killed. The north and Viet Cong suffered much more: around 1,100,000 killed plus an unknown number of wounded. Estimates for civilian deaths are 1 - 3 million Vietnamese, plus 200,000 - 300,000 Cambodians and 20,000 - 200,000 Laotians.
After the war, the north laid a heavy hand on the south, leading to a stream of refugees in the 1970's CE. Not until 1986 CE did Vietnam partially reverse its communist course and opened up again. In the USA, unaccustomed to losing wars, the conflict caused an almost nation-wide trauma. Morale in the army plummeted and led to the adoption of a volunteer army after 1973 CE.