MSNBC journos are speculating.
Tillerson: Pre-emptive force an option with North Korea
Past U.S. administrations have considered military options against North Korea and have publicly said that an attack on the U.S. or its allies would prompt a devastating response.
Tillerson's comments were unusual, however, as he appeared to be implying, in public, that the U.S. would consider military force as a way of preventing an attack by Pyongyang, and not just as a means of retaliation.
It also comes amid a greater sense of urgency about the threat because of North Korea's rapid progress toward developing the means to strike the U.S. with a nuclear-tipped missile.
Risks of military action are high as North Korea could unleash a massive artillery barrage on Seoul in retaliation.