Washington must present a credible threat to Pyongyang, while leaving the door open to talks.

If President Trump decides he wants business as usual with North Korea, he will be playing a losing hand. More progress is likely to be made if he plays the role of peacemaker rather than disrupter.

The United States is approaching a critical juncture in its policy towards North Korea. However, throwing in the towel on diplomacy is premature until it has been seriously tested, particularly since the downsides of military action are enormous.

Donald Trump could have an opportunity early in his presidency to prove his negotiating skills on a serious national-security challenge the United States will confront over the next four years.