China’s Wedge Strategies toward the U.S.-South Korea Alliance

• In Event: Military and Economic Interdependence

Abstract

A great power uses wedge strategies to divide hostile alignments, to shift the balance of power. A wedge strategy dynamic involves three actors: the great power choosing wedge strategies (the divider), the adversary that poses threat to the divider, and the target state that is aligned with the adversary. How does the divider choose different types of wedge strategies? This study argues that the combination of the divider’s leverage over the target and its threat perception determines its choice.

When considering its wedge strategies, the divider worries about the risk of balancing blowback, the risk that the divider’s wedge strategies unite rather than divide the target and the adversary. Coercive wedge strategies will increase the divider’s threat against the target and thus incentivize it to stand close to the adversary. Thus, when the divider has strong leverage, it chooses accommodative wedge strategies as its primary strategy to induce the target and reduce the risk of blowback. Meanwhile, the divider also worries that the target may want to draw the divider and the adversary into a bidding war, in which they attempt to outbid each other by offering more rewards to the target. Therefore, the divider uses coercion to complement its accommodative strategies, to signal that its accommodation has limits and that it does not intend to enter a bidding war for the target’s allegiance.

If the divider’s leverage over the target is weak, its accommodation may be insufficient to alter the target’s cost-benefit analysis and the second variable, threat perception, would determine the divider’s choices of strategies. The divider perceives threat from security cooperation between the adversary and the target. While the adversary is the major source of threat, security cooperation between the adversary and the target increases the aggregated capabilities of the adversary’s camp and thus poses greater threat to the divider. Such cooperation at a high level could pose serious threat to the divider. Consequently, the divider will choose coercive strategies as its primary strategies. Meanwhile, the divider will use accommodation as the complementary strategy to provide the target with an assurance: the divider will stop coercion if the target complies with its demands.

This study tests this theory with China’s use of wedge strategies toward South Korea between 2012 and 2018. Dissatisfied with the U.S. presence in its periphery, China used wedge strategies to weaken the U.S.-South Korea alliance. With increased military and economic capabilities, China enjoyed strong leverage over South Korea. Consequently, China chose accommodation as its primary strategy and coercion as its complementary strategy. However, in 2016 the United States enhanced its pressure on South Korea to deploy the THAAD system and weakened China’s leverage. Meanwhile, the THAAD deployment suggested enhanced security cooperation between the United States and South Korea. As a result, between 2016 and 2018 China switched its primary strategy to coercion and its complementary strategy to accommodation.

This study contributes to our understanding of wedge strategies. Different from the existing literature, I argue that states often choose mixed strategies rather than pure strategies. Moreover, this study also has policy implications. As China and Russia are trying to undermine the U.S. alliance system in East Asia and Europe, findings of this study further our understanding of China and Russia’s strategic choices. Meanwhile, the United States may use wedge strategies to divide China and Russia. This study also sheds light on factors that decision-makers would consider when choosing strategies.

Author

• Chengzhi Yin, Syracuse University