North Korean leader Kim Jong Un has promoted his 28-year-old sister, Kim Yo-Jong, to the ruling party’s political wing, bringing her closer to the center of power and tightening the family’s control on the regime. She was made an alternate member of the politburo, replacing her aunt, Kim Yong Hee, who was an important decision maker when her father, Kim Jong Il, was still alive. Only hours after U.S. President Donald Trump said “only one thing will work” in dealing with the isolated country, Kim Jong Un said his nuclear weapons are a “powerful deterrent” which guarantee North Korea’s sovereignty.