Logic of Choice: How do States Decide Their Wedge Strategies

• In Event: Poster Session: International Security II

Abstract

Wedge strategy—a strategy of preventing or dividing adversarial alliances—is an important tool for balance of power. States use wedge strategies to prevent their adversaries from aggregating capabilities against them. While this topic has drawn increasing scholarly attention. the puzzle that how states choose specific wedge strategies remains understudied. To add, the existing literature suggests that states choose between reward-based and coercion-based wedge strategies. Will states always choose pure strategies? If not, under what conditions do state choose mixed strategies?

This research develops a theory of wedge strategy to answer those questions. Assume three actors: the divider, the target state, and the divider’s adversary. The theory argues that two independent variables determine the choice of wedge strategies: divider’s leverage over the target, and the degree of security cooperation between the target and the adversary. Leverage is defined as the divider’s ability to influence the target’s foreign policy-making; the degree of security cooperation is defined as the ability of the target and the adversary to agree on their objectives and strategies toward achieving those objectives. As to strategic choices, the divider can choose between “coercion,” using actual or threatened punishments, and “accommodation,” using actual or promised rewards. Importantly, the divider can choose a pure strategy or a mixed strategy.

When choosing wedge strategies, strong leverage will prompt the divider to choose accommodation due to the concern about the spiral dynamic. Using coercive wedge strategies against the target stimulates target’s perception of threat from the divider. This threat perception, in turn, adds to target’s incentives to align with the adversary. Thus, the divider’s coercive wedging unites rather than divides its adversaries. To avoid this sell-fulfilling prophecy, the divider will prefer accommodation. Meanwhile, the divider is likely to choose coercive wedging as the complementary strategy, unless the divider lacks ability to do so. This is because the divider can use coercion to signal that its accommodation is restrained and it does not intend to fight a bidding war for the target’s allegiance. However, if the divider’s leverage is weak, the degree of security cooperation between the target and the adversary determines the divider’s wedge choices. The higher the degree of such security cooperation, the more likely China is to use coercion.

To test this theory, this research conducts a detailed case study of China’s wedge strategies toward Vietnam between 1975 and 1979. China, as the divider, tried to drive a wedge between Vietnam, the target, and the Soviet Union, the adversary. Employing archival materials, this research shows that when China had strong leverage over Vietnam, China chose to accommodate Vietnam while using coercive wedging as the complementary strategy. However, when gradually losing its leverage, China estimated the degree of security cooperation between Vietnam and the Soviet Union. When the degree of such cooperation was high, China chose coercive wedge strategy while using accommodation as a complement. With the degree of such cooperation increasing, China was devoting more efforts to coercive wedging and the role of accommodation was diminishing.

Author

• Chengzhi Yin, Boston College