What US options are ‘on the table’ with North Korea?

Secretary of State Rex Tillerson has signaled that the U.S. will take a more aggressive approach to North Korea's missile and nuclear program, including possibly through pre-emptive military action. "All options are on the table," particularly if North Korea continues making advances in its ballistic missile and nuclear weapons technologies, Tillerson said last week at a news conference in Seoul. "If they elevate the threat of their weapons program to a level that we believe requires action,...