Kim Yo-jong's Rising Power May Undermine Trump's North Korea Diplomacy

Donald Trump has signaled his willingness to sit down again with North Korean leader Kim Jong Un, reviving the possibility of high-level talks that once captivated the world. The two men met three times between 2018 and 2019, exchanged letters Trump himself called love notes, and the former president became the first sitting U.S. president to cross into North Korean territory. Yet those summits produced no breakthrough on denuclearization, no lasting peace agreement, and no fundamental shift in the regime's nuclear ambitions. Now, as Trump hints at a return to that diplomatic playbook, analysts and experts are raising a different concern: the person who may matter most in determining whether talks happen at all is not Kim Jong Un, but his sister.

Kim Yo-jong emerged into public view during the 2018 Winter Olympics in South Korea, where she presented a softer face of North Korea to international observers. Photographs showed her smiling alongside South Korean President Moon Jae-in. The South Korean press was charmed. Experts now regard that performance as calculated theater. Since then, she has assumed control of North Korea's propaganda and agitation apparatus, a position from which she has hurled insults at South Korea's leadership with remarkable venom. She has called the South Korean presidential office a "frightened dog barking" and worse, labeled former President Park Geun-hye with a crude sexual slur, and dismissed a former defense minister as "senseless and scum-like." Sung Yoon Lee, a North Korea specialist and author, has called her the most dangerous woman in the world, and he does not say this lightly.

What makes Kim Yo-jong's rise particularly significant is the question of who actually drives policy in Pyongyang. Their father, Kim Jong Il, once told a Russian diplomat that his sons were "idle blockheads." He passed over his eldest son, Kim Jong Chol, deeming him too "effeminate" to lead. Kim Jong Un, the chosen successor, has shown a taste for basketball and luxury that sometimes seemed to rival his interest in statecraft. Kim Yo-jong, by contrast, has never wavered from politics. Educated partly in Switzerland, raised in wealth and privilege, she has focused her entire adult life on power. Analysts believe she is not merely an advisor to her brother but the strategic mind behind the regime's most consequential decisions. Some experts assess that she is positioning herself to become North Korea's next leader, a prospect that would represent an unprecedented break from the regime's patriarchal tradition.

The timing of Trump's diplomatic overture coincides with a dramatic shift in North Korea's posture and capabilities. The regime has grown emboldened by its deepening military partnership with Russia, which has provided both validation and material support. North Korea has accelerated its nuclear weapons program to a point where it now possesses approximately 50 warheads and enough fissile material to produce as many as 40 more, according to the Stockholm International Peace Research Institute. Where the regime once downplayed its involvement in the war in Ukraine, it now openly celebrates North Korean soldiers killed in combat. Its rhetoric toward South Korea has become more aggressive, its language toward the United States more assertive. The calculus that might have motivated engagement in 2018 no longer applies.

Kim Yo-jong's strategy has evolved accordingly. During the Olympic charm offensive, she pursued what experts describe as fake peace overtures—diplomatic gestures designed to lower South Korea's guard while the regime continued its weapons development unabated. That phase has ended. Now she appears focused on direct escalation, cultivating an image of ruthlessness among North Korea's elite and signaling to the world that the regime has no interest in the kind of negotiated settlement that failed before. When South Korea's new president, Lee Jae Myung, took office with a more conciliatory approach and both countries began dismantling propaganda loudspeakers at their shared border, Kim Yo-jong responded not with reciprocal goodwill but with denial and dismissal. She flatly rejected that North Korea had removed any loudspeakers and reiterated the regime's lack of interest in improving relations with the South.

President Lee has expressed hope that Trump's personal relationship with Kim Jong Un could serve as a foundation for renewed diplomacy, and Trump himself appears to believe that the rapport he built with the North Korean leader remains intact. But the architecture of North Korean power has shifted since their last meeting. Women now occupy positions of genuine influence in the regime in ways that would have been unthinkable under Kim Jong Il or his father before him. Choe Son Hui serves as North Korea's first vice minister of Foreign Affairs. Pak Myong Sun heads the Light Industry Department and sits on the Politburo. Kim Yo-jong stands above them all, controlling the narrative and, by most accounts, shaping the decisions that matter most. There is also speculation that Kim Jong Un's twelve-year-old daughter, Ju Ae, is being groomed as a potential successor, another departure from the regime's historical preference for male inheritance. Yet experts believe Kim Yo-jong's ambition and ruthlessness position her as the more likely heir. If Trump's strategy depends on convincing Kim Jong Un to return to the negotiating table, he may discover that the real obstacle is not the man he once called "little rocket man," but the woman who stands behind him.