In Vietnam, in 1967, William Chickering commanded a Mike Force battalion of Montagnards, highland tribesmen who were also members of a secret army, FULRO. Some senior American commanders worried that FULRO was communist, but those who fought with them understood that the goal of the United Front for the Liberation of Oppressed Races was to drive all Vietnamese—including communists—from the highlands. For a while, FULRO appeared capable of changing the course of the war in Vietnam. Then, inexplicably, it faded away.

Chickering’s quest to understand FULRO took him to Phnom Penh in 1973, where he found five of the six leaders, the sixth having been mysteriously murdered. He was unable to discern the truth behind their political smoke, and just two years later, 150 of them—men, women, and children—disappeared into the maw of the Khmer Rouge. Among them was the family of Bhan, one of the leaders, who had been in the United States when Phnom Penh fell.

In 1986, Bhan headed back to Southeast Asia to learn their fate. He resurfaced in Cambodia 22 years later, after an extraordinary odyssey. He had never found his family. Were they, and the rest of the FULRO Montagnards, executed by the Khmer Rouge, or could they still be alive, somewhere in Cambodia? Determined to finally unveil the truth, Chickering moved to Phnom Penh. His research led him to the widow of a Cambodian Cham widely assumed to have been FULRO’s sinister puppeteer, and eventually to FULRO’s secret papers. From these he was able to piece together why FULRO faded away, and how FULRO’s failure was connected to its one last heroic shot in 1965 to win a country for the Montagnards.

This extraordinary account reveals a previously untold aspect to the Vietnam War: how a minority with dreams of reclaiming their homeland used the protagonists in a wider conflict to try and further their own ends, and almost succeeded.