One of the security challenges facing the United States (US) is the US and North Korea relations. The US policy toward North Korea is diplomatic yet firm. North Korea is our longest standing adversary. Policy toward North Korea is one of the most enduring foreign policy challenges. In this essay I will discuss the security challenge of U.S. and North Korea, the theory of international relation, realism, how it illuminates this challenge and how the instruments of power can be utilized to address this challenge. The stability U.S. relations with North Korea are closely tied to how stable relations are between North Korea and South Korea. According to our lesson, North Korea threatens South Korea, Japan and economic ties through the region (Instructional Narrative, 2012, 8). A nuclear North Korea, armed with ballistic missiles capable of reaching Japan, represents Tokyo’s immediate challenge (Corin, 2009, 265). The instability of North Korea ranks among the most complex of contemporary challenges to international security (Przystup, 2009).…