When Robert Cecil, the future Lord Salisbury and Conservative prime minister, infamously referred to India in 1867 as an “English Barrack in the Oriental seas” he was not suggesting this arrangement's desirability. The less well-known portion of his speech proved as pessimistic as it was prophetic, “it is always bad for us not to have a check upon the temptation to engage in little wars which can only be controlled by the necessity of paying for them.” Cost distribution theory ties together two historical developments that cannot be explained by existing explanations in IR and historiography: the expansion of the British franchise deep into the middle class in 1867 and into the working class in 1884, and the explosion of imperial military campaigns (often against the better judgment of the government) over the same period of time. The two Reform Acts' large and sudden reductions in the wealth requirements for voting represent clear and discrete changes in the value of my key explanatory variable, the relative income of the median voter. It is therefore a natural case for establishing both the plausibility of the book's causal mechanism and the theory's usefulness in explaining important cases of democratic militarism, among which the late Victorian British Empire surely belongs.

More specifically, cost distribution theory sheds light on the links between a number of important developments occurring during this period, including:

1. (i) Massive increases in suffrage and corresponding decreases in the wealth of the average voter in Britain.

2. (ii) The growing obsession with the defense of India even as it developed into a strategic liability.[…]