first one that comes to mind is Operation Cyclone - he armed the reactionary mujahideen in afghanistan to impede the USSR's support of the nascent Democratic Republic of Afghanistan
Unfortunately, despite its professions of support for human rights in Indonesia, the Carter Administration picked up where Kissinger and Ford had left off. As Noam Chomsky writes in the preface to Matthew Jardine's 1995 book, East Timor: Genocide in Paradise, "In 1977, Indonesia found itself short of weapons, an indication of the scale of its attack. The Carter administration accelerated the arms flow."[7] U.S. arms sales hit $112 million in 1978, and averaged nearly $60 million per year for the four years of the Carter administration -- this was more than twice the level of weaponry supplied to the Suharto regime by the Ford Administration.
Reagan and the wave of conservative world leaders in the 80s made it the new status quo, but Jimmy Carter is often credited as the first neoliberal president and the starting point of neoliberalism in the US.
He knew what was happening in Cambodia, too. He said something along the lines of "Pol Pot is bad, but a necessary evil to stop Vietnam's communism from spreading."
I don't know what's worse than children being euthanized because they need glasses or teachers/professors getting public executions for being teachers/professors. And AFAIK, it's the largest killing in history based on population. Something like 25% of Cambodians were killed by the Khmer Rouge.
Jimmy Carter exiting with grace at the last chance to have a state funeral with dignity.
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Edit
I muted "Carter" at Bluesky but there's a sea of this shit.
Upon a former President's death, the flag should be flown at half-mast for 30 days. I'm going to bet even-money that Trump refuses to honor this after his inauguration.