In the past few months, multiple illegal North Korean ballistic-missile and ICBM tests—coupled with the most recent bellicose language from Pyongyang about striking the U.S., Guam, our allies and our interests in the Asia-Pacific region—have escalated tensions between North Korea and America to levels not experienced since the Korean War.

In response, the Trump administration, with the support of the international community, is applying diplomatic and economic pressure on North Korea to achieve the complete, verifiable and...