Review

Kim Yo Jong Is the World’s Most Dangerous Woman

A new book profiles the possible future leader of North Korea.

By , the senior director of the nonproliferation and biodefense program at the Foundation for Defense of Democracies.
Kim Yo Jong
Kim Yo Jong
Kim Yo Jong, the sister of North Korean leader Kim Jong Un, attends a wreath-laying ceremony at Ho Chi Minh Mausoleum in Hanoi on March 2, 2019. Jorge Silva/Reuters

He needs to “shut his mouth.” That was the advice Kim Yo Jong, the powerful sister of North Korean leader Kim Jong Un, gave to South Korean President Yoon Suk-yeol after his offer to provide economic aid to Pyongyang in exchange for nuclear disarmament. In the just-released book The Sister: North Korea’s Kim Yo Jong, the Most Dangerous Woman in the World, South Korean scholar Sung-Yoon Lee chronicles the younger Kim’s rise to power within the North Korean system and expertly describes her function as the regime’s de facto deputy leader. A closer look at Kim Yo Jong is long overdue, for she appears well-positioned to become the paramount leader of a nuclear-armed state one day.

He needs to “shut his mouth.” That was the advice Kim Yo Jong, the powerful sister of North Korean leader Kim Jong Un, gave to South Korean President Yoon Suk-yeol after his offer to provide economic aid to Pyongyang in exchange for nuclear disarmament. In the just-released book The Sister: North Korea’s Kim Yo Jong, the Most Dangerous Woman in the World, South Korean scholar Sung-Yoon Lee chronicles the younger Kim’s rise to power within the North Korean system and expertly describes her function as the regime’s de facto deputy leader. A closer look at Kim Yo Jong is long overdue, for she appears well-positioned to become the paramount leader of a nuclear-armed state one day.

A deep dive into the often inscrutable dynamics of the Kim family and the North Korean elite can be intimidating for the nonexpert reader. Lee is a Korean studies professor and can draw on his deep expertise in the Korean Peninsula’s politics; he also attended the International School of Geneva at the same time as Kim Yo Jong’s half-brother, Kim Jong Nam. In the first-ever book that focuses solely on Kim Yo Jong, Lee provides meticulously researched color and detail, helpfully accompanied by a family tree and chart of the principal characters. His book is a clinical narrative but also comes with a strong point of view: He does not hide his disdain for Kim Yo Jong and her facilitation of her brother’s many atrocities against the country’s population. As the book’s cover notes, Lee considers her to be the most dangerous woman in the world.

Lee begins Kim Yo Jong’s story with an explanation of the “Mount Paektu bloodline,” the official North Korean propaganda term for the ruling dynasty that has devastated the North Korean people for more than 70 years. The North Korean narrative details how Kim Il Sung, Kim Yo Jong’s grandfather and the country’s founder, used Korea’s highest mountain as a staging area for guerrilla operations to defeat the Japanese colonial masters in 1945. Lee calls it a “fictitious narrative” that serves as the “ideological foundation” of the Kim family’s rule.

huge statues of Kim Il Sung and Kim Jong Il
huge statues of Kim Il Sung and Kim Jong Il

North Koreans pay their respects to statues of Kim Il Sung and Kim Jong Il at the Mansudae Grand Monument in Pyongyang, North Korea, on Aug. 19, 2018.Carl Court/Getty Images

Understanding the North Korean regime’s obsession with the Kim family bloodline helps explain Kim Yo Jong’s and her brother’s exalted status above the rest of the elite. In Korean culture, Mount Paektu is imbued with mythical significance, and, as Lee explains, by locating the Kim dynasty’s imaginary origins there, that mythical power is extended to them. As quasi-mythical figures, the Kims reign at the top of a strict class hierarchy also determined by birth—a classification system known as songbun, or “birth status,” that divides North Koreans into three broad categories. As Lee writes, they are “the favoured Core Class, the middle Wavering Class, and the lowest Hostile Class (as well as over fifty subclasses).”

Just as the Kims’ origin narrative makes them born to rule, most North Koreans acquire their place in the songbun hierarchy by birth. It determines “where you live, your education, your job, and your food rations,” Lee writes. The Core Class includes North Korean elites and other generally trusted regime supporters. Laborers, farmers, and business owners are in the Wavering Class, Lee explains, and are placed under general surveillance. Koreans repatriated from Japan, those who flee North Korea, and religious people are relegated to the Hostile Class.

But Lee illuminates what he calls three dark secrets that the Kim family keeps hidden from the North Korean people for fear that their exposure could topple the regime. The first is that Kim Yo Jong and Kim Jong Un’s mother, Ko Yong Hui, was born in Japan. Second, one of their aunts defected to the United States in 1998. And finally, Kim Il Sung’s parents were Christian, with his mother a deaconess.

None of these family factoids would be remarkable in a normal country. But in a society where one’s place in the hierarchy stems from guilt by association, the existence of any one of these relatives would mark any other North Korean for the Hostile Class and perhaps destined for hard labor or a concentration camp.

Kim Jong Un and Kim Yo Jong escaped that fate and remained at the top of the hierarchy. Throughout the book, Lee explains that Kim Yo Jong has been far more than just a face at her brother’s party meetings. Kim Jong Un might be the main “face of the nation,” he writes, but his sister is the “chief censor” and “enforcer.” Lee describes her sinister role as the head of the powerful Propaganda and Agitation Department, which controls and directs all North Korean media. Lee also highlights that under Kim Yo Jong, North Korean propaganda leveled “vile, racist invective[s]” toward then-U.S. President Barack Obama, saying he was a “wicked black monkey” and a “crossbreed with unclear blood”—illustrating the Kim family’s obsession with bloodlines again. Former South Korean President Park Geun-hye, according to North Korean media, was a “dirty old prostitute.”

Former U.S. Vice President Mike Pence and Kim Yo-Jong at the olympics
Former U.S. Vice President Mike Pence and Kim Yo-Jong at the olympics

U.S. Vice President Mike Pence (front right) and Kim Yo Jong (back left) watch the opening ceremony of the Winter Olympic Games at Pyeongchang Olympic Stadium in Pyeongchang, South Korea, on Feb. 9, 2018. Matthias Hangst/Getty Images

Lee uses Kim Yo Jong’s February 2018 visit to Pyeongchang, South Korea, for the Winter Olympics to highlight her real power in the regime. South Korean Unification Minister Cho Myoung-gyon met with the delegation shortly after their arrival. North Korea’s nominal head of mission motioned for Kim Yo Jong to take the seat opposite Cho, reinforcing that Kim was in charge, even if she was not the formal head of the delegation. (She demurred and took another seat.) Lee explains that official ranks and titles matter little in North Korea, where “the lives of cabinet members and four-star generals often hang on the whims of a real powerholder of a much lower rank.”

Her reception in South Korea was largely positive, with the local media gushing over her appearance and manner—a successful hoodwinking, Lee argues. Even the New York Times was blinded by Kim Yo Jong’s charms, contrasting her supposed “messages of reconciliation” with the “old message” of confrontation delivered by the highest-ranking U.S. guest, then-Vice President Mike Pence.

Following the Olympics, Kim Yo Jong accompanied her brother to multiple summits with the leaders of South Korea, China, and the United States. But these engagements did not produce a diplomatic breakthrough, and Kim Yo Jong returned to the old playbook of verbally attacking South Korea. Lee highlights that in June 2020, Kim Jong Un unofficially elevated his sister to de facto deputy leader, whereby, according to Lee, “her words were his words, vetoable only by him.” In March 2020, Kim Yo Jong made the first public statement in her own name, dismissing South Korean President Moon Jae-in’s criticism of North Korean military drills, calling it “perfectly foolish” and the work of a “three-year-old.”

Leaders from North and South Korea in a conference room
Leaders from North and South Korea in a conference room

South Korean President Moon Jae-in (center left) attends the inter-Korean summit with Kim Jong Un (center right) and Kim Yo Jong (front right) in the Demilitarized Zone separating North and South Korea on April 27, 2018. Korea Summit Press Pool/AFP via Getty Images

She doubled down three months later. Saying she was exercising the power authorized by her brother, she ordered the destruction of North-South liaison buildings just north of the border. Lee explains that the buildings were maintained with South Korean funds of more than $15 million. That same month, she also demanded that South Korea stop its citizens from sending propaganda leaflets across the border, one of the few holes in North Korea’s totalitarian control over what its citizens are permitted to know and a potential crack in the regime’s narrative. Moon, eager to calm relations, accepted Kim Yo Jong’s demands, effectively allowing her to extend “her repressive nation’s censorship” across the entire Korean Peninsula, Lee writes.

Kim Yo Jong has recently been engaged in dismissing the United States, which suggests an expanded role in the regime. She responded forcefully to the Washington Declaration by Yoon and U.S. President Joe Biden in April to strengthen U.S. nuclear commitments to South Korea. Kim Yo Jong called Yoon a “fool” and Biden senile. In July, she threatened “shocking” consequences if the United States continued reconnaissance flights near North Korea. Later that month, she rejected the U.S. National Security Advisor Jake Sullivan’s overtures for talks, warning Washington to avoid “foolish” acts.

Lee concludes the book by explaining that Kim Yo Jong is well-placed to wield power for decades, whether as Kim Jong Un’s deputy or successor. Given the opaque and secretive nature of the North Korean system, the book does not provide any detail on the precise maneuverings for power, potential signs of conflict between Kim Yo Jong and her brother, or what kind of foreign policy she might pursue. It remains unclear how North Korea’s male-dominated elites, including the military, would react to the first woman to lead their country. Meanwhile, Kim Jong Un has confounded observers who believe Kim Yo Jong is first in line for the succession by beginning to elevate his own 11-year-old daughter, letting her accompany him to an intercontinental ballistic missile launch and other military visits. That could be a sign that he plans to pass the country to one of his children, as his father and grandfather did.

Kim Yo Jong may feel secure based on her membership in the Kim dynasty. But the overall theme throughout Lee’s book offers a cautionary tale: The only person in North Korea who is truly secure is the leader—after all, Kim Jong Nam’s position in the family dynasty did not prevent Kim Jong Un from having him killed with VX nerve agent in an airport in Malaysia. If Kim Jong Un passes the country to his daughter, even Kim Yo Jong’s vaunted bloodline may not save her.

Books are independently selected by FP editors. FP earns an affiliate commission on anything purchased through links to Amazon.com on this page.

Anthony Ruggiero is the senior director of the nonproliferation and biodefense program at the Foundation for Defense of Democracies and a former senior director for counterproliferation and biodefense on the U.S. National Security Council during the Trump administration. Twitter: @NatSecAnthony

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