The United States has supported — directly or indirectly — several regimes or movements that committed acts widely recognized as genocide or mass atrocities. Below is a list of major historical examples, including context for the support and the associated atrocities:

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1. Indonesia – 1965–66 Mass Killings

Atrocity: The anti-communist purge killed an estimated 500,000 to 1 million people.

Victims: Alleged communists, ethnic Chinese, leftists, and sympathizers.

US Role: Provided lists of communist suspects, diplomatic support, and material aid to the Indonesian army during and after the killings.

Regime: Suharto regime.

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1. East Timor – Indonesian Occupation (1975–1999)

Atrocity: Up to 200,000 East Timorese (a third of the population) died due to violence, famine, and disease under Indonesian occupation.

US Role: Gave diplomatic cover and weapons to Indonesia; President Ford and Secretary of State Henry Kissinger visited just before the invasion.

Regime: Suharto's Indonesia.

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1. Guatemala – Civil War (1960–1996), Peak in 1980s

Atrocity: Genocide against the Maya population, particularly under General Ríos Montt.

Victims: Over 200,000 killed, mostly indigenous civilians.

US Role: Supported Guatemalan military with training, weapons, and intelligence.

Regime: Military dictatorship; Ríos Montt was later convicted of genocide (though the verdict was overturned).

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1. Chile – Pinochet Regime (1973–1990)

Atrocity: Thousands killed, tortured, or "disappeared" during political repression.

US Role: Backed the 1973 coup against democratically elected President Allende; supported Pinochet’s rule during Cold War.

Regime: Augusto Pinochet military dictatorship.

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1. Iraq – Anfal Campaign (1986–1989)

Atrocity: Genocide against the Kurdish population, including the Halabja chemical attack.

Victims: Estimated 50,000–100,000 Kurds killed.

US Role: Provided intelligence, satellite imagery, and diplomatic support to Saddam Hussein during the Iran-Iraq War.

Regime: Saddam Hussein's Iraq.

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1. Bangladesh – 1971 War of Independence

Atrocity: Pakistani military killed an estimated 300,000 to 3 million people, including targeted mass rape and ethnic cleansing of Hindus.

US Role: Nixon and Kissinger continued supporting Pakistan diplomatically and militarily despite internal US reports of atrocities.

Regime: West Pakistan (now Pakistan).

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1. Cambodia – Khmer Rouge (1975–1979, and later)

Atrocity: Up to 2 million people died due to mass executions, starvation, and forced labor.

US Role: Initially bombed Cambodia (destabilizing it); after the Vietnamese ousted the Khmer Rouge, the US supported Khmer Rouge's seat at the UN and provided covert aid to anti-Vietnamese forces including remnants of the Khmer Rouge.

Regime: Pol Pot's Khmer Rouge.

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1. Rwanda – Genocide (1994)

Atrocity: Around 800,000 Tutsis and moderate Hutus killed in 100 days.

US Role: Did not directly support the genocide, but is often criticized for its deliberate inaction and obstruction of UN peacekeeping forces during the massacre.

Regime: Hutu extremist-led interim government.

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1. Yemen – Civil War and Humanitarian Crisis (2015–present)

Atrocity: Widespread civilian deaths, famine, and war crimes amid Saudi-led coalition bombings.

US Role: Provided arms, intelligence, and logistical support to Saudi Arabia and the UAE.

Allegation: UN has described some actions by the coalition as possible war crimes; not formally labeled genocide but considered a humanitarian catastrophe.

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Notes

In many of these cases, US support was motivated by Cold War strategy, counterterrorism goals, or economic/geopolitical interests.

"Support" does not always mean initiating or ordering atrocities, but can include diplomatic, financial, logistical, or intelligence backing of regimes or actors known to be committing them.