Unified Korea and the Future of the U.S.-South Korea Alliance

December 11, 2015


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South Korea

United States

North Korea

Political Transitions


Korean unification could arguably occur within the next decade. No other country in the world is as diplomatically isolated as North Korea. Even its closest ally and benefactor, China, is showing signs of becoming increasingly intolerant of the North's saber rattling and brinkmanship tactics. On diplomacy and economic competition, the North is losing badly. South Korea is often cited as a successful model of economic and political development in the developing world, whereas North Korea is one of the world's poorest nations; having experienced a massive famine in the 1990s, the country now subsists on handouts from China. Cracks are also appearing in the edifice of the North Korean state, as the regime's ability to control the flow of outside information to ordinary citizens diminishes. In December 2013, the country's third-generation dictator Kim Jong-un executed Jang Song-thaek, his uncle and the second-most-powerful man in the regime, on charges of plotting against the leader. Kim has also executed more than seventy other high-ranking officials since coming to power. Although popular uprisings of the kind that toppled governments from East Germany and the Philippines to Egypt, Libya, and Tunisia are still unlikely in North Korea, these events are a reminder that sudden change is always possible and it is impossible to predict exactly when the North Korean state would collapse. Within the next five-to-ten years, a cascading series of events could conceivably end with regime collapse in the North, leading to the unification of the two Koreas.  

Unification would constitute one of the most decisive changes in the history of Northeast Asia since the outbreak of the Korean War in 1950, with far-reaching implications for the United States and the balance of power in the region. Assuming that unification does not result from a devastating war, a Korea unified in the next five to ten years would likely emerge as a consumer and industrial powerhouse with a well-educated and hardworking population of approximately seventy-five million people, considerable natural resources (mostly in the North), advanced technology, armed forces that are among the largest and most capable in the world, and, possibly, nuclear weapons. In addition, Korea's policymakers would need to address an important issue about their country's future: whether to remain closely aligned with the United States, draw closer to China, or adopt an independent posture, balancing between the two Pacific giants.

In the first decade or two following unification, Korea would be preoccupied with nation-building in the North, stabilizing it politically and economically, demobilizing and decommissioning the North Korean military, closing the vast economic disparity between the two Koreas, and melding two societies that have diverged for seventy years or more. The likely strategic orientation of a unified Korea after the completion of the initial phase should be of considerable concern not only to Koreans, both North and South, but also to their neighbors—China, Russia, Japan—and to the United States. The future direction of a unified Korea's foreign policy could affect the balance of power in Northeast Asia. Unless the unification process backfires and produces a crippled, inward-focused state—an unlikely outcome—a unified Korea is likely to be more politically and economically influential in both regional and global affairs than either South or North Korea is today.

Given the inevitability of unification, the United States should take steps now to increase the likelihood that the U.S.-South Korea alliance would survive the disappearance of North Korea. If Washington failed to act to lock in its relationship with Seoul, the United States could face the risk, in a post-unification world, that Korea could either align with China or, more likely, pursue an independent foreign policy, maintaining equidistant relations with the United States and China.

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