As before, Mr. Trump’s statement did not make clear what would constitute an action that would require an American military operation — would the United States take action only in retaliation for an actual attack by North Korea, or would it strike to stop further development of nuclear weapons?
Last month for the first time, North Korea successfully tested intercontinental ballistic missiles capable of reaching the continental United States, and analysts have said it may be able to miniaturize warheads that could fit on such missiles.
Still, even if it has, North Korea faces additional hurdles before it would be able to launch a nuclear attack on the United States, among them ensuring that a warhead could survive the ravages of re-entry through the atmosphere. But the progress it has made has unnerved much of Asia, prompting a new set of sanctions by the United Nations Security Council.
Mr. Trump this week vowed to rain “fire and fury like the world has never seen” down on North Korea if it threatened the United States. After critics in both parties called that sort of language excessive and reckless, Mr. Trump doubled down on Thursday by saying that “if anything, maybe that statement wasn’t tough enough.”
Defense Secretary Jim Mattis, asked Thursday about the American military’s readiness for action, said: “I don’t tell the enemy in advance what I’m going to do. Our readiness, we are ready.”