Half a century later, disturbing new details of a conflict once dubbed the “forgotten war” are challenging official history in South Korea. Since September, when the Associated Press published an account alleging that American soldiers massacred 300 civilians under a railway bridge in No Gun Ri in 1950, new claims of atrocities have surfaced across the country. To date, South Korea’s Defense Ministry has received no fewer than 37 written appeals to investigate alleged mass killings involving U.S. troops. But the most painful revelations involve what the Koreans did to each other: last week President Kim Dae Jung signed legislation authorizing a parliamentary inquest into a 1948 purge targeting pro-Pyongyang communists in which 30,000 leftists and their families were massacred. “This represents an opening of the South Korean political system,” says former Washington Post reporter Don Oberdorfer, a Korea expert at Johns Hopkins University and a member of an American fact-finding team investigating No Gun Ri. “And like Pandora’s box, out of it is coming tales of disaster and outrage from the war in Korea.”

These revelations come at a delicate moment. In Washington, where President Bill Clinton has promised full disclosure on No Gun Ri, officials worry that an inquiry launched last December might broaden into a battle-by-battle review of U.S. conduct during the war. If the investigation is mishandled, it could undermine support for the 38,000 U.S. troops now deployed in South Korea. “It certainly is not possible to go back and look at every incident where there was loss of innocent life,” U.S. Army Secretary Louis Caldera told journalists during a visit to South Korea last week. South Korean generals who had hoped to commemorate the 50th anniversary of the Korean War in triumph now fear that talk of massacres could ruin the moment. “War, by nature, is unlimited destruction,” retired Air Force Gen. Kim Dong Ho told NEWSWEEK.

But democracy and the end of the cold war have sparked a review of Korean propaganda. After decades of admitting no wrong (and branding all who dared to suggest otherwise as communists), Seoul suddenly is examining its record. Victims of indiscriminate bombings and political executions are stepping forward. Koreans are learning that both sides–not just the communists–committed atrocities. “People see it as the good guys on one side and the bad guys on the other,” says Bruce Cumings, an authority on Korean War history at the University of Chicago. “But there are so many stories in Korea, and it’s much more complicated than that.”

Located 150 kilometers south of Seoul, Taejon epitomizes the double-edged inhumanity. The town’s large prison was bursting with accused leftists by the time war broke out. Rather than leave the prisoners to be freed by their comrades, police opted for mass executions. According to Cumings, Washington’s decision to hide this “gross atrocity” constitutes “American complicity after the fact.” When the North took Taejon, the conquerors filled the jail with rightists. Barely two months later, as Northern armies retreated ahead of an American counteroffensive, troops executed some 1,300 prisoners, drowning many of them in a nearby well.

The planned parliamentary investigation of the communist rebellion in Cheju Island could change South Korea’s concept of the war–and, ultimately, Seoul’s views of the North. According to war historians, Seoul’s decision to crush a Worker’s Party organization on Cheju surely contributed to Pyongyang’s decision to launch a blitz southward in 1950.

Of the complaints filed against American forces–most by victims of aerial bombardments–No Gun Ri remains the most serious. The claim, recently substantiated by American veterans, holds that GIs knowingly gunned down a column of refugees, killing an estimated 300 people, many of them women and children. The U.S. troops may have opened fire out of fear of infiltration. But some Koreans think that GIs angered by losses and the capture of their commander massacred the refugees because they “were enraged at Korean civilians,” says a Seoul Defense Ministry official. “The context is important,” says U.S. investigator Oberdorfer. “On the other hand, it should not give us an excuse.”

In a forthcoming book, novelist Hwang Sok Yung will examine the killing of thousands of civilians in Shin Chon, his ancestral home in North Korea. Exhibits in the town’s GI Massacre Museum charge that American troops were “more brutal than Hitler.” According to Pyongyang, GIs slaughtered 33,383 residents during a 45-day occupation in 1950. Hwang believes that mass killings indeed took place. But there’s a twist. He says the killers weren’t American soldiers. Instead, Korean rightists, many of them Christians, emerged from hiding to massacre the communists. “In the 1980s, we harbored a naive anti-Americanism,” he says. “Now we are looking back at the war and our history in a more mature way.” The painful process has only begun.