Abstract
Over the past 10 years, South Korea has chosen inconsistent strategies with respect to the US–South Korea alliance. On the one hand, Seoul disagreed with Washington about the extended role of United States Forces Korea and the deployment of US missile defence systems in East Asia. On the other hand, these problems ironically coincided with South Korea’s strong support for the USA in operations in Afghanistan and Iraq. What explains the inconsistency of South Korea’s alliance policies? Major schools of thought in international relations have offered explanations, but their analyses are deficient and indeterminate. This article looks at the South Korea–China–North Korea triangle as a new approach to explaining the puzzling behaviour of South Korea. The model shows that South Korea’s alliance policies are driven by two causal variables. First, North Korea is an impelling force for South Korea to remain as a strong US alliance partner. This encourages Seoul to maintain cooperation with Washington in wide-ranging alliance tasks. Second, South Korea’s policies are likely to reflect the way the nation perceives how useful China is in taming North Korea. The perceived usefulness of China causes Seoul to accommodate China and decrease cooperation with the USA. This might strain the relationship with the USA should South Korea evade alliance missions that might run contrary to China’s security interests.