Ken Kolsbun, a peace symbol historian, believes the design’s simplicity played a role in its continued success. “You can have a 5-year-old draw it,” he said in a phone interview.

Peace: The Biography of a Symbol by Ken Kolsbun. National Geographic HK$260. Those who grew up in the west in the 1960s or 1970s might remember scrawling the circular peace symbol on a school ...