A half century has passed since the Chilean military carried out a coup that overthrew democratically elected president Salvador Allende and unleashed a reign of terror that lasted 17 years.

To mark this milestone, American lawmakers today introduced a resolution in the House and Senate that expresses “profound regret” for the U.S. government’s role in supporting the Chilean dictatorship.

Senators Bernie Sanders and Tim Kaine and Representatives Alexandria Ocasio-Cortez, Joaquin Castro, Greg Casar, and Nydia Velázquez initiated the resolution. These House members and a senior Sanders aide traveled to South America last month for meetings with Chilean officials, including Chile’s student movement leader-turned president, Gabriel Boric.

The legacy of U.S. involvement in the region “loomed large” over these meetings, Ocasio-Cortez said in a press release. “The U.S. cannot credibly show up as a trustworthy partner that can help advance democracy in the present if we don’t own up to our complicated past,” she added.

The resolution is historic as a formal statement of regret for the role of the Nixon administration in destabilizing Chile to create the conditions for the coup and then helping General Augusto Pinochet strengthen his brutal grip on power. His regime tortured some 40,000 people and killed more than 3,000, including nearly 1,500 who were “disappeared” and presumed dead.

U.S. official reluctance to own up to this history was evident in 2003, the 30th anniversary of the coup, when a student asked then-Secretary of State Colin Powell for his view. Powell’s off-the-cuff response: “It is not a part of American history that we’re proud of.” The State Department immediately issued a statement distancing the department from the words of their own top official.

Rep. Jamie Raskin will present a copy of the resolution to President Boric at a public event in Washington, D.C. on September 23. The 37-year-old Chilean leader will deliver an address at Sheridan Circle, the site of the 1976 assassination of Institute for Policy Studies colleagues Orlando Letelier and Ronni Karpen Moffitt.

At the Institute, Moffitt worked as a development associate while Letelier advocated for more equitable international economic policies. A former Chilean ambassador to the United States, Letelier had also become one of the most prominent critics of dictator August Pinochet.

On September 21, 1976, Moffitt and Letelier were driving to the office when agents of Pinochet detonated a bomb strapped to the bottom of Letelier’s car. Before 9/11, their assassination was the most infamous act of international terrorism in the capital city.

Since this horrific attack, the Institute for Policy Studies has organized gatherings at Sheridan Circle and an annual Letelier-Moffitt human rights awards program to remember these fallen heroes and lift up new champions.

These gatherings have also served as moments to take stock of the significant progress over the past 50 years on the path to justice and accountability. The just-introduced U.S. Congressional resolution is the latest in a long string of milestones.

In the Letelier-Moffitt case, Saul Landau led an independent Institute for Policy Studies investigation into the crime to keep up pressure on American authorities. Between 1978 and 1991, seven people faced U.S. prosecution for their roles in the crime.

After Chile’s transition to democracy in 1990, two former generals, Manuel Contreras and Pedro Espinoza, were sent to prison in Chile for their roles in the crime. The Chilean government also settled the first wrongful death suit against a foreign nation, on behalf of the Letelier and Moffitt families.

The big bombshell came in 1998, when London police arrested Pinochet on an order from the Spanish courts. This astounding achievement struck fear in the hearts of dictators around the globe. Former Secretary of State Henry Kissinger, who’d orchestrated the Nixon administration’s support for Pinochet, even canceled a trip to Brazil for fear he’d be “pinocheted.”

After more than a year of house arrest, UK authorities let Pinochet return home on medical grounds. But when he died in 2006, he was facing multiple criminal charges.

Pinochet’s arrest also amplified demands for declassification of relevant U.S. government documents. The Clinton administration responded with the release of more than 16,000 documents that further illuminated U.S. support for the dictatorship and generated evidence for legal cases against numerous human rights violators.

In an interview with TIME magazine, President Boric explains how the former dictator’s arrest was a huge eye-opener for him. Just 12 years old at the time, he was confused by women in the news accusing Pinochet of having made their relatives “disappear.” He wondered: Was Pinochet a magician?

His search for an answer led him to the revelations about the dictatorship that set him on a political path. He was a leader of the Chilean student movement that rocked the country with demands for bold progressive change, including replacement of the Pinochet-era constitution. This upheaval catapulted Boric to power in 2021.

Recently, in a move that brings his 12-year-old research full circle, Boric announced an investigation into the more than 1,000 Chileans “disappeared” by the dictatorship whose remains have never been found. He’s also notched a few economic policy advances, including raising royalties from the country’s mining sector, funds that will be invested in communities affected by resource extraction.

But Boric also faces tremendous obstacles, including right-wing, authoritarian forces similar to those behind the insurrection at the U.S. Capitol. It’s not surprising, then, that the Congressional resolution also commits American lawmakers to working with the Chilean people in the future to defend democratic institutions.

“As we mark the 50th anniversary of the horrific coup in Chile, we must make clear that we regret our involvement and commit to supporting Chilean democracy,” Senator Sanders said. “To build the lasting partnerships we need in this hemisphere, we will need to establish a basis of trust and respect. Part of that process includes full accountability for the coup and its aftermath.”