Seattle author Blaine Harden has an uncanny ability to uncover stories about men whose lives become a portal through which to better understand the United States-North Korea conflict. In his two previous nonfiction bestsellers, Harden wrote about a boy who escaped a North Korean concentration camp in “Escape from Camp 14” and then about a North Korean air force pilot whose defection to the West had a major influence on the Korean War in “The Great Leader and the Fighter Pilot.” Now, in his latest account, “King of Spies: The Dark Reign of America’s Spymaster in Korea,” Harden tells the true story of an American who was both a war hero spymaster and a murderer with inappropriate ties to a foreign leader, President Syngman Rhee of South Korea.

According to Harden, Major Donald Nichols was a king of spies who played an outsized role in the Korean war. By providing the U.S. Air Force with most of its targets in North Korea, Nichols enabled the relentless bombing and napalming of North Korean cities, a story the Kim family uses to stoke American hatred to this day. His almost familial relationship with President Rhee, the founding leader of South Korea, sheds new light on the conflicts on the Korean Peninsula and on high-level lies and cover-ups that have lasted for nearly a half-century.

Harden learned about Nichols during his interviews with Ken Row, the subject of his second book. As a North Korean pilot, Row knew Nichols’ name.

“Row knew a lot about Nichols from the North Korean military, which sent assassins to try to kill the American spy, but Nichols’ name never appeared in The New York Times or Washington Post,” Harden said in a recent interview. “He was unknown to the American press, even though he was the most important and longest serving foreign intelligence operative for 11 years before, during and after the war.”

While Nichols broke the North Korean battle codes, found weakness in Soviet tanks and Meigs, and located the targets for the U.S. Air Force, he also “had legal license to murder.”

“He was 27 years old, amoral, ambitious and aggressive with a seventh-grade education,” Harden said. “It didn’t take long before he was a major who reported only to a general who gave Nichols his own base, 1,000 spies and his own rules.”

A complicated character as war hero and spy, involved in both helping and hurting people in a “confused and bloody war,” Nicholas died alone in a psychiatric ward of a VA hospital in Alabama. His story dramatizes a dark chapter in U.S. history and helps explain North Korea’s ongoing animosity toward America.

“In a sense, Nichols was America’s Kurtz,” Harden said. “Like the ambitious and self-destructive figure in Joseph Conrad’s ‘Heart of Darkness,’ Nichols operated beyond the bounds of legality, morality and, if the U.S. Air Force psychiatrists are to be believed, beyond the bounds of sanity.”