This volume identifies the pattern of military spending in the Southeast Asian region over the past ten to fifteen years and provides explanations for the variations in spending rates. Two overview essays evaluate the role of threat perceptions and systemic variables on the shaping of defence spending while a third examines the methodological problems involved in assessing defence expenditures. In the case studies that follow, eight Southeast Asian countries are looked at systematically to see how their heterogeneous defence spending patterns are shaped by factors such as the geopolitical environment, the sense of threat and vulnerability, the decision-making structures, the military procurement patterns, and external affiliations.