Backgrounder by the Council on Foreign Relations–

Recent Developments

North Korea’s government has continued its aggressive and erratic behavior, as demonstrated by recent military and cyber provocations, and continued efforts to develop nuclear weapons and long range missiles. In addition to harming its own citizens, the country’s actions threaten the entire Korean peninsula.

In September and January 2016, North Korea conducted its fourth and fifth nuclear weapons test, claiming to have detonated its first hydrogen bomb in January. However, analysis of the seismic readings and radiation left doubt as to what type of weapon was actually tested. Continuing to defy international sanctions, in February 2016 Pyongyang fired a long-range rocket to launch a satellite into orbit, an move that was widely viewed as a continuation of testing of intercontinental ballistic missile technologies and that has further increased tensions. These actions have elicited serious concerns, with new U.S. sanctions passed in February 2016 following additional punitive measures taken by Japan and South Korea. Still, North Korea continues to test neighboring countries and their allies, and remains determined in its proliferation of both nuclear and conventional weapons. In March 2016, North Korea announced that it had created a nuclear device small enough to fit on a ballistic missile, a claim that remains unconfirmed. Three months later, in June 2016, North Korea succeeded in testing a Musadan intermediate range missile. This test came in the wake of four previous failures, but its recent success represents a significant growth in North Korean weapons technology. Moreover, the Musadan missile has now expanded North Korea’s threat radius well outside of the Korean peninsula, to include Japan, Guam, and U.S. Navy vessels operating in the Pacific theater.


North Korea (officially known as the Democratic People’s Republic of Korea) is isolated, impoverished, and a proclaimed enemy of its southern neighbor—an important U.S. ally.

U.S. military involvement in the Korean peninsula has its roots in the Korean War of the early 1950s, in which the United States supported forces in the southern part of the peninsula against communist forces in the north, who were aided militarily by China and the Soviet Union. Today, the United States is committed to defending South Korea (also known as the Republic of Korea) under the terms of the Mutual Defense Treaty between the United States and the Republic of Korea. The United States has nearly 29,000 troops deployed in the Korean peninsula for that purpose. In addition to U.S. troops, many of South Korea’s 640,000 soldiers and North Korea’s 1.2 million soldiers are stationed near the Demilitarized Zone (DMZ), making it one of the most heavily armed borders in the world.

In violation of UN Security Council resolutions, North Korea continues overt nuclear enrichment and long-range missile development efforts. Although the scope of North Korea’s uranium enrichment program remains uncertain, U.S. intelligence agencies estimate that it has enough plutonium to produce five nuclear weapons.

In addition to the recent January 2016 nuclear test, North Korea has previously tested nuclear weapons on three other occasions in October 2006, May 2009, and February 2013. All of these tests have taken place within the remote mountainous test site at Punggye-ri and the magnitude of these nuclear devices has grown with each subsequent test.

Outside of the nuclear realm, North Korea also maintains a large missile stockpile and research program and continues to test these weapons despite UN Security Council Resolutions prohibiting this behavior.

North Korea is believed to possess one thousand missiles of varying capabilities and ranges including:

  • Nodong – 1,300km
  • Taepodong 1 – 2,000km
  • Musudan –  4,000km
  • Taepodong 2 – 8,000km

Kim Jong-un, North Korea’s Supreme Leader, has consistently proven to be both impulsive and irrational. These conditions exacerbate the threat from North Korea’s weapons proliferation as Kim often incites the West with his aggressive behavior. Some of these incitements have included firing rockets across the South Korean border in August 2015, cyberattacks on U.S.-based Sony Pictures in December 2014, and shelling of South Korea’s Yeonpyeong Island in 2010.

Kim has also undertaken efforts to consolidate his power by purging high-ranking officials, including his own family members. There are reportedly between 80,000 and 120,000 political prisoners detained in North Korea.


North Korea is a nuclear power with a complex relationship with China, and preventing both an interstate Korean war and a North Korean internal collapse are critical U.S. national security interests. Small-scale military and cyber provocations by North Korea pose significant risks as each incident carries with it the potential for escalation. Outright threats from North Korean Supreme Leader Kim Jong-un are also cause for concern.