SEOUL — As the U.S. and South Korea celebrate the 70th anniversary of their alliance this year, they will consider how their partnership, frequently characterized as "ironclad," is preparing for the challenges of the future.
One traumatic experience from the past that is likely to shape South Korea's response to future challenges resurfaced in February. That's when a South Korean court made an unprecedented ruling in an unusual court case dating back to the Vietnam War. The court ruled in favor of a Vietnamese woman who had sued South Korea's government over a massacre committed by South Korean soldiers in her village 55 years ago.
South Korea, then ruled by a military leader, sent some 320,000 troops to fight alongside the U.S. in Vietnam, the largest contingent of any U.S. ally.
On Feb. 12, 1968, South Korean marines entered the village of Phong Nhi in South Vietnam's Quang Nam province. It was less than two weeks into the Tet offensive, launched by North Vietnamese and Viet Cong troops, and the marines were looking for Viet Cong fighters.
Nguyen Thi Thanh, 8 years old at the time, says the marines gunned down residents indiscriminately. She and her family members fled into an underground bomb shelter.
"The Korean soldiers found us and forced us to come out," she tells NPR in an interview from Vietnam. "If we didn't, they would have dropped a grenade into the shelter. That was a terrifying situation."
But the terror only worsened. "Everyone started to come out, and as they did, they were shot, one by one."
Now 63, Nguyen says South Korean marines killed more than 70 people in her village and a neighboring one.
Nguyen's mother, two brothers, a sister and cousin were among them. She was shot in the waist.
"I wish I had been killed with my mother," she says, "because it became a horrible obsession for me."
That obsession led to her decision to sue the South Korean government three years ago.
Her case was championed by South Korean civic groups, lawyers and journalists who broke the story of the village massacre in 1999. Nguyen first visited Seoul in 2015, at the invitation of civic groups, and returned this year to testify in court.
A former South Korean marine who entered Nguyen's village also testified on her behalf. That ex-marine, Ryu Jin-sung, says his unit took fire as they approached Phong Nhi, and one marine was wounded. In guerrilla warfare, he says, distinguishing combatants from innocents is always hard.
"You can't tell whether someone's an innocent civilian or an enemy spy," he says in an interview in his Seoul office. "So the easiest way was to kill everyone."
A key part of Ryu's testimony in court involved what he heard after the massacre from his fellow marines.
"After we had returned to the base, fellow platoon members talked about their killings in vivid detail, as if they were some sort of heroic tales."
U.S. Marines were also in the area, and some entered Phong Nhi some four hours after the South Koreans, where they photographed dead and wounded villagers.
A U.S. military report on the incident noted that "there was some probability that a war crime was committed" by the South Korean marines.
Less than a month after this attack, U.S. troops massacred more than 500 unarmed civilians in the hamlet of My Lai, the worst known U.S. atrocity of the Vietnam War. U.S. Army Lt. William Calley Jr. was later convicted of personally murdering 22 Vietnamese civilians.
For many South Koreans, a court finding their government responsible for a massacre marked a painful historical moment. Many previously had thought of themselves as victims — of Japanese colonial rule from 1910 to 1945, and of North Korea's invasion during the 1950-1953 Korean War.
For other Koreans, including civic groups that supported plaintiff Nguyen Thi Thanh, it was a necessary step towards righting wrongs committed under the military governments that ruled South Korea from 1961 to 1988.
"What civil society argues most strongly is that we need to face up to our past," says Seoul National University historian Park Tae-gyun. "We always say we are the victims of Japanese imperialism and demand apology from Japan, but we are not looking squarely at the damages we have done."
Over 5,000 South Korean troops died in the Vietnam War, and many more were injured or traumatized. Park says these troops can be viewed as victims mobilized by their government — but also as perpetrators.
South Korea dispatched forces to Vietnam partly to repay the U.S. for defending the South in the Korean War, Park says, and partly to keep the U.S. from pulling its own troops from South Korea and into Vietnam.
The U.S. paid Seoul some $5 billion in wages and assistance from 1965 to 1973. U.S. military procurement, meanwhile, helped South Korean conglomerates including Hyundai grow into industrial giants.
South Korea's experience in Vietnam emerged as part of the public debate 20 years ago, when Seoul decided to dispatch troops to the U.S.-led war in Iraq. South Koreans protested this decision, but the president at the time made the case that sending troops to Iraq would earn Seoul political capital with Washington that could help resolve tensions with North Korea. In the end, South Korean troops formed the third-largest contingent in the coalition forces, after the U.S. and Great Britain.
South Korea's Vietnam War experience could also affect how Seoul responds to potential future requests from Washington for assistance, Park says, as the U.S. increasingly looks to mobilize allies for future contingencies — especially a possible conflict with China over Taiwan.
As unprecedented as the court decision was in Nguyen Thi Thanh's case, it is unclear what, if any, effect the decision will have on government policy.
On Feb. 8, a Seoul court ordered the South Korean government to compensate Nguyen Thi Thanh $24,000. But the government will appeal the court's ruling. Defense Minister Lee Jong-sup denied that South Korean marines had massacred anyone.
Nguyen praised the court's verdict, and slammed the minister's remarks.
"By saying that, I think he has lost his humanity," she says. "He should come to my village and hear the stories the villagers tell about their family members who died under the South Korean soldiers' guns."
Former marine Ryu Jin-sung, meanwhile, says some of his fellow veterans have attacked him over his court testimony.
"A part of me doubted whether I did the right thing for the country and for our society," he muses, "whether what I did was something to be proud of — or whether I should've just kept my mouth shut."
NPR's Se Eun Gong contributed to this report in Seoul.