Aquestes dades, divulgades per R.J. Rummel, demostren que des de l'any 1816 no hi ha hagut cap guerra entre democràcies, d'un total de 371 conflictes armats registrats. En totes aquestes guerres, com a mínim un dels dos bàndols era sempre un país no democràtic. Només hi ha hagut 3 excepcions:
Two of these involved Peru and Ecuador in 1981 and 1984 (26 to 100 killed in the first, and 1 to 25 in the second case of violence). In 1981 Peru was only marginally democratic, as was Ecuador, but less so. This was also true of Peru and Ecuador in 1984. The only other case of violence over these near two centuries was marginally democratic Ecuador (initiator) vs. the U.S. in 1954 in which 1-25 were killed. Only three cases, and none since 1984 despite there being 117 democracies today.