Kim Jong Un promoted four of his closest advisers to North Korea’s powerful ruling body over the weekend, signaling that the young leader is eager to surround himself with loyalists working to affirm his rule over the isolated country that has been controlled by his family for decades. With the move, Kim rewarded his foreign minister and two of the three men behind North Korea’s rocket program, as well as his younger sister. The power shuffle comes as the United States and North Korea have traded heated rhetoric for months, raising concerns that the two nuclear-armed nations could set off a global conflict that could result in the death of millions of people. Most recently, North Korea said Saturday its nuclear weapons could be used for self-defense, while President Donald Trump said last week that “only one thing will work” in quelling Kim’s nuclear ambitions. Trump didn’t clarify his remarks. The words have been met with action and further threats, with North Korea launching missiles over Japan and carrying out its sixth nuclear test in recent months. In a speech before the Central Committee of the ruling Workers’ Party on Saturday, Kim told party leaders that the nation’s nuclear weapons…