Determinants of Hybrid War Tactics in Southeast Asia's Rivalries

Thesis Abstract

The study investigates the determinants of hybrid war tactics within Southeast Asia’s rivalries, addressing the rising prominence of coercive political methods that blend conventional and non-conventional tools in regional security dynamics. It contends that hybrid strategies emerge from the interaction of strategic rivalries, external influence, domestic political incentives, information environments, and capability asymmetries, which collectively shape the adoption, adaptation, and escalation of hybrid tactics. The aim is to empirically identify the key drivers of hybrid war tactics and map their relative influence across Southeast Asian security actors, with attention to how regional norms, alliance commitments, and economic interdependencies modulate tactic selection. Specific objectives are (1) to quantify the association between interstate rivalry intensity and the deployment of hybrid tactics; (2) to assess the moderating role of external powers and security guarantees on hybrid tactic utilization; (3) to examine domestic political economy factors—elite incentives, regime type, and public opinion—influencing hybrid strategy choices; (4) to analyze information environments, including misinformation campaigns and strategic communications, as precursors or catalysts of hybrid actions; (5) to compare the prevalence and variation of hybrid tactics among major regional actors (e.g., state and non-state proxies) and across basins (South China Sea, Andaman Sea, and Malay Archipelago). The research employs a mixed-methods design. The quantitative strand uses a cross-national panel dataset covering 2005–2024 for ten Southeast Asian states, with a sample of 120 country-year observations meeting data completeness criteria. Variables include rivalry intensity (measured by militarized interstate disputes and defense expenditure asymmetries), external sponsorship indices, regime type, economic interdependency, and hybrid tactic incidence (coded from incident reports and official statements). Regression analyses, including fixed-effects and hierarchical linear modeling, test hypotheses about direct and interaction effects, while robustness checks employ propensity score matching to address endogeneity. The qualitative strand conducts in-depth case studies of three pivotal rivalries (Vietnam–China, Malaysia–Indonesia, and Thailand–Myanmar) using process-tracing and thematic analysis of official documents, strategic communiqués, state-controlled media, and open-source intelligence to illuminate mechanisms linking antecedents to tactic choices. Data collection instruments comprise a structured coding scheme for hybrid incidents, semi-structured interview guides with defense analysts and policymakers, and a document analysis protocol. Validity is strengthened through triangulation across datasets, intercoder reliability checks (Cohen’s kappa above 0.80 for coded variables), and pilot testing of survey instruments. The expected findings indicate that rivalry intensity positively correlates with hybrid tactic deployment, with external sponsorship amplifying, and domestic political incentives shaping the selection between coercive, covert, and informational components. Information environment factors—especially disinformation campaigns and strategic narratives—are anticipated to mediate deterrence and escalation dynamics, accelerating hybrid actions in periods of perceived strategic vulnerability. The study contributes to knowledge by offering a contextualized, empirically grounded model of hybrid warfare determinants in a rapidly evolving interstate system, integrating frames from constructivist and realist theories, notably employing Schmittian conceptualizations of the “state of exception” alongside Nye’s information power and Jomini-inspired deterrence dynamics to interpret tactic choices. The findings are expected to reveal nuanced regional variations reflecting differing alliance commitments, economic linkages, and institutional capacities, challenging universalist accounts of hybrid warfare. Policy implications include recommendations for regional confidence-building measures, norms against information manipulation, and tailored alliance strategies that reduce coercive value of hybrid tactics while maintaining credible deterrence. The study concludes that hybrid war tactics in Southeast Asia are best understood as outcomes of interacting structural rivalry, external influence, political economy pressures, and information environments, with regional specificity governed by institutional resilience and strategic communications capabilities. Recommendations emphasize enhanced transparency in defense spending, robust cyber and information-domain norms, improved early-warning indicators for hybrid escalations, and collaborative regional monitoring frameworks to detect and deter hybrid aggression before it escalates into overt conflict.