Abstract
This dissertation contends that public opinion, reflected in audience costs, matters in authoritarian states’ foreign policy signalling. Audience costs can arise and accumulate in episodes of protest, often informed by social media, where the authoritarian state decides to engage with its public, co-opt protesters to signal resolve, or repress them. Audience costs are fundamentally underpinned by a causal logic of consequences that requires any regime, be it authoritarian or liberal democratic, to respond. A case study of Vietnam’s disputes with China in the South China Sea from 2007 to 2019 demonstrates that audience costs were in operation in Vietnam’s foreign policy signalling toward China. The costs were contextual, at once high, cumulative, and observable. The degree of success in signalling resolve and generating deterrent values depended on the magnitude and observability of the costs. The core aspect of domestic audience cost mechanisms is the level of consensus in Vietnam’s domestic polity. This thesis suggests that future research consider consensus costs as a more useful concept than audience costs when examining the relationship between domestic politics and foreign policy signalling.