“War is hell; the less of it the better. Yet it has also been a near constant feature of human history, and a constant stimulus to political evolution. Defence is a textbook example of a public good. Security benefits all residents of a country, and cannot be denied to citizens who prefer not to pay for it. There is little incentive for private forces to provide defence – unless by doing so they can take over the right to extract compensation from the society they protect. Throughout history, the legitimate government is the one that can best defend its people.
As populations have grown and technology has advanced, the job of defending societies has become more complex. That, in turn, has spurred the proliferation of government responsibilities. Research by Nicola Gennaioli and Hans-Joachim Voth suggests that the growing financial demands of warfare after 1500 helped drive the formation of large, strong nation-states in Europe. The rising cost of war meant that keeping a state secure required a powerful, centralised government capable of raising large sums of money—through tax, or via modern, central bank tended financial systems. Their work draws on research by Timothy Besley and Torsten Persson, who reckon state power built to improve defence can yield better economic policy; the capacity to use the tax system to transfer wealth directly, for instance, means society relies less on inefficient sorts of redistribution.” (The Economist, 2017, p.63).
The Economist (2017) In Times of Peace, Governments Grow Complacent. The Economist. 29 April, 2017.