The shared threat emanating from Pyongyang creates a centripetal force that binds Washington, Tokyo, and Seoul because the three partners need mutual assistance. On the other hand, however, the high stakes involved in the North Korea policy of these states also intensify discord over the means to address the threat, thereby producing a centrifugal force. Policies that hurt each other’s fundamental security interests have to be pursued only with careful consultation with the partners, for both the policies’ effectiveness and for the maintenance of the partnerships. For effective cooperation, the U.S., Japanese, and ROK governments must all embrace the centripetal force of the North Korean threat while being mindful of the centrifugal force.