The life expectancy of all political systems depends, among other factors, on the ability to resist military pressure and other means of coercion, that is, to mount and sustain a sufficient ‘security-related effort’(SRE). Yet over the last decades, SRE in the West has increasingly fallen short of what is required, especially vis-à-vis the main systemic competitor, the Soviet bloc. This trend can be explained by the interplay of two kinds of long-term change in Western societies. The first is the gradual penetrating and remoulding of their structures by capitalism, replacing both threat and integrative relations by exchange as a social organizer and thus delegitimizing the military (and other means of organized coercion), and at the same time rendering war much more destructive and costly by harnessing modern science and technology to the design and production of weaponry. The second process is the diffusion of representative, subsequently democratized, systems of government: decision-making by representative assemblies generates, via the mechanism of log-rolling, allocative decisions biased towards providing private goods (e.g. by tax reductions), merit goods, and transfer payments, and consequently disfavouring public goods such as deterrence of potential aggressors.