WELLINGTON, New Zealand—Australian Prime Minister Scott Morrison said Wednesday that Australia will join the US in a diplomatic boycott of the Beijing Winter Games over human rights concerns. Morrison said it should come as no surprise that Australian officials would boycott the event after the nation’s relationship with China had broken down in recent years. “I’m doing it because it’s in Australia’s national interest,” Morrison said. “It’s the right thing to do.” He said Australian athletes would still be able to compete. As well as citing human rights abuses, Morrison said China had been ver…