Them’s fightin’ words. As the USS Carl Vinson and two Japanese ships gathered for military exercises in the Western Pacific, North Korea said it’s ready to sink American ships and won’t hesitate to strike Australia if it remains allied with the United States. Chinese President Xi Jinping called for restraint from both North Korea and President Donald Trump this morning. Meanwhile, an American stopped from leaving North Korea this weekend has been identified as Kim Sang-duk, a professor at a Pyongyang university. It’s not yet clear why he’s been detained.