Southeast Asia Timeline
How did conflicts and politics in Southeast Asia and neighboring Vietnam, as well as United States policies, affect Cambodian history in the last 50 years—and vice versa? View a timeline to learn more.
Japan surrenders to Allied forces in World War II and Ho Chi Minh and his People’s Congress declare Vietnam’s independence. The following year, former colonizer France recognizes Vietnam as a free state.
After remaining French troops in North Vietnam fail to defeat Ho Chi Minh’s Communist Vietminh forces, China and the Soviet Union both offer weapons and support to the Vietminh. The United States responds by sending 15 million dollars in aid to the French.
After 80 years of colonialism, Cambodia wins independence from France. Twenty-two-year-old King Norodom Sihanouk returns from exile to become the leader of the newly established country of Cambodia. Saloth Sar, who will later be known as Pol Pot, establishes a Communist party in Cambodia after studying in Paris.
Laos also wins its independence from France.
Vietnam is divided into North and South by the Agreement on the Cessation of Hostilities in Vietnam.
Sihanouk steps down from the throne to become prime minister. He pledges Cambodia’s neutrality as the Cold War escalates in Southeast Asia. However, the United States wants to use Cambodia as a buffer against North Vietnam and Communist influences in the region.
Following a series of defeats by the Vietminh, French forces leave Vietnam. The U.S. military assumes responsibility for training South Vietnamese forces.
A Communist insurgency in South Vietnam starts, with the assassination of more than 400 South Vietnamese officials. North Vietnamese Communist forces settle along the Mekong Delta and eventually begin to move weapons into South Vietnam through the Ho Chi Minh Trail.
In the North Vietnamese city of Hanoi, the National Liberation Front for South Vietnam is established and dubbed “Vietcong.”
John F. Kennedy defeats Richard Nixon for the U.S. presidency by a narrow margin.
As North Vietnamese forces begin attacks on South Vietnamese troops, the U.S. Air Force begins to use Agent Orange on the Vietcong.
U.S. spy planes reveal Soviets planting offensive missiles on Cuban land. President Kennedy enacts quarantine around Cuba to halt additional missiles from the Soviet Union. The Cuban Missile Crisis becomes a major event in the Cold War.
The Communist Party of Kampuchea, a secretive organization with Pol Pot as one of its leaders, flees to the countryside from Phnom Penh to launch a guerrilla insurgency. Sihanouk dismisses the faction, nicknaming them the Khmer Rouge.
The assassination of President Kennedy puts the issue of how to proceed in Vietnam into the hands of now-president Lyndon Johnson.
Lyndon Johnson is elected president in a landslide victory over Republican opponent Barry Goldwater. Johnson’s position of de-escalating American military involvement in Vietnam—while later proving to be untrue—appeared less militant than Goldwater’s views.
After North Vietnamese boats allegedly fire torpedoes at the U.S.S. Maddox, a destroyer in the Tonkin Gulf off of the North Vietnamese coast, the U.S. Congress approves the Gulf of Tonkin Resolution, which allows President Lyndon Johnson to wage war against North Vietnam without a formal Declaration of War.
U.S. Marines land in South Vietnam and the first battle of the Vietnam War takes place in the Ia Drang Valley. By the end of the year, there are 200,000 U.S. troops in Vietnam.
The United States begins its secret bombing campaign on Cambodia, directed against Vietnamese targets. Over the next eight years, the U.S. would drop 2.7 million tons of bombs on Cambodia, killing up to 500,000 civilians.
Sihanouk breaks off diplomatic relations with the U.S. and becomes a closer ally to North Vietnam.
The Vietcong and the North Vietnamese Army are operating along the South Vietnamese and Cambodian border with Sihanouk’s approval.
U.S. forces, having begun bombing North Vietnam, increase efforts to destroy Vietcong operations in South Vietnam’s Saigon.
The Khmer Rouge forms a peasant insurgence against a rice tax, but is suppressed by the government army.
The North Vietnamese launch the Tet Offensive upon South Vietnam. U.S. and South Vietnamese try to recapture the sites seized during the Battle for Hue, effectively leveling the city.
In March, U.S. troops massacre civilians in the village of My Lai, later known as the My Lai Massacre. Anti-war demonstrations begin in the United States.
With anti-war sentiments building and his popularity falling, President Johnson announces that he will not run for re-election. In November, Richard Nixon narrowly beats Hubert Humphrey for the presidency.
President Nixon begins “Operation Breakfast,” a covert bombing of Cambodia.
Massive anti-war demonstrations take place in Washington, D.C.
Sihanouk restores diplomatic relations with the U.S., but is ousted from power while traveling abroad by Lon Nol, a pro-American general.
In April, American and South Vietnamese forces cross into Cambodia without Lon Nol’s knowledge. Civil War rages in Cambodia. In the United States, the American “secret invasion” of Cambodia results in anti-war protests, including the deaths of student protesters shot by the National Guard at Kent State University. President Nixon withdraws American troops from Cambodia, but continues bombing the country for another three years.
U.S. forces bomb Hanoi and Haiphong in North Vietnam. President Nixon reduces troops in Vietnam by 70,000.
Nixon is re-elected president.
A ceasefire is signed in Paris and the last American troops leave Vietnam.
In the U.S., the Senate begins hearings on the Nixon administration’s bombing of Cambodia during a time when Cambodia was recognized to be neutral. Congress orders that all U.S. bombing in Cambodia stop on August 14.
The Khmer Rouge gains power with assistance from China and North Vietnam. Even Sihanouk, who is living in exile, publicly supports them as opponents of the American-backed puppet government. Resistance against the U.S. bombing also increases the Khmer Rouge’s popularity.
Impeachment hearings begin against President Nixon. The articles of impeachment include not only the Watergate scandal, but also a resolution that condemns Nixon for the secret bombing of Cambodia. Nixon later resigns, and Vice President Gerald Ford takes his place.
The Khmer Rouge takes control of Cambodia, declares it Year Zero and begins its doomed vision of agrarian utopia. In the next four years, two million Cambodians die from overwork, starvation, torture and mass executions.
In Vietnam, North Vietnamese forces capture the city of Saigon, which is later renamed Ho Chi Minh City. South Vietnam surrenders and the city falls to the Communists. Millions of Vietnamese flee the country during the fall of Saigon. Having anticipated the Communist takeover of Saigon, President Ford announces that the Vietnam War is “finished” with regards to the United States.
The United States finally recognizes the brutality of the Khmer Rouge regime as President Jimmy Carter calls it “the worst violator of human rights in the world.”
Vietnam invades Cambodia to halt attacks along the border and overthrow the Khmer Rouge.
In January, Vietnamese troops enter Phnom Penh. The Khmer Rouge retreats to the jungle near the Thai border.
Norodom Sihanouk forms a coalition in exile with the Khmer Rouge against the new Vietnamese-backed Cambodian government. Despite President Carter’s earlier declarations against the Khmer Rouge, the United States gives millions of dollars in aid to this coalition and helps the Khmer Rouge maintain its seat in the United Nations—a diplomatic move against Vietnam and Vietnam’s Soviet allies.
For more than a decade, a guerilla war continues between the U.S.-supported Sihanouk-Khmer Rouge coalition and the Vietnamese-supported Cambodian government. Hundreds of thousands of Cambodians flee to refugee camps in Thailand and Vietnam. Between 1979 and 1989, nearly 150,000 Cambodians arrive in the United States.
Vietnamese troops leave Cambodia.
After the warring factions in Cambodia sign a peace agreement, United Nations peacekeepers arrive to back the reinstatement of a constitutional monarchy. In May, U.N.-supervised elections are held and a new constitution is ratified. Norodom Sihanouk takes the throne, while his son, Prince Norodom Ranariddh, shares the office of prime minister with former Khmer Rouge member Hun Sen, who served as prime minister under the Vietnamese-backed government.
The U.S. Congress passes the Cambodian Genocide Justice Act, which calls for bringing Khmer Rouge leaders to trial for war crimes.
The Cambodian government offers amnesty to former Khmer Rouge foreign minister Ieng Sary, Pol Pot’s brother-in-law. Ten thousand Khmer Rouge members—half of the group’s remaining members—also defect and receive amnesty.
Hun Sen ousts co-prime minister Prince Ranariddh in a bloody coup.
The Khmer Rouge splits into further factions. Former comrades capture Pol Pot and renounce him in a “people’s tribunal.” He is placed under house arrest.
In April, Pol Pot dies at the age of 73.
Former Khmer Rouge military commander Chhit Choeun, a.k.a. Ta Mok, is arrested by the Cambodian army and charged with genocide. He is later also charged with crimes against humanity.
Kang Kek Ieu, former Khmer Rouge chief of the notorious prison and extermination center Tuol Sleng, also known as Duch, is charged with murder.
U.N. officials begin talks on setting up a genocide tribunal to try former Khmer Rouge leaders.
Cambodia holds its first multi-party local elections. Hun Sen’s Cambodian People’s Party gains the majority vote.
Cambodia has a gross domestic product of three billion dollars U.S. and a debt of two billion dollars.
After years of negotiations, the U.N. and the Cambodian government reach an impasse regarding the genocide tribunal.
The Cambodian National Assembly approves the Law on the Establishment of the Extraordinary Chamber in preparation for the Khmer Rouge genocide trials.
Cambodia’s U.N.-backed court detains former Khmer Rouge leaders Duch; Ieng Sary and his wife, Ieng Thrith, who was minister for social affairs; Nuon Chea, who had also previously defected and been granted amnesty; and Khieu Samphan, the former Khmer Rouge head of state. The five defendants are charged with war crimes and crimes against humanity. Trials are set to begin in late 2008.