North Korea is frustrated, isolated and uncertain about its future. Kim sat down with President Donald Trump in 2018 and 2019 and tried to use North Korea’s nuclear capabilities as leverage to get the U.S. to lift or ease the sanctions. It didn’t work. So Kim has tried to force the Americans back to the negotiating table. To do that, he has to test weapons, ratcheting up the threat to the U.S. and its allies. That’s a major reason for North Korea to build up its capabilities now; it has to have a deep arsenal to be able to negotiate...