„In my ‘Understanding Conflict and War’ I concluded that the more freedom a state accords its citizens, the less likely it is to be involved in foreign violence; and the more freedom within two states, the less likely there will be violence between them. Moreover, war between free-libertarian-states will not occur, and other violence between them is very improbable… This conclusion about the violence-reducing effect of freedom also extends to conflict within states: ‘the more libertarian a state, the less intense its violence can and tends to become.“
“Libertarianism, Violence within States, and the Polarity Principle,” Comparative Politics, Vol. 16, No. 4 (Jul., 1984), pp. 443-462. Published by Comparative Politics, Ph.D. Programs in Political Science, City University of New York. https://www.hawaii.edu/powerkills/DP84.HTM