Other Democratic Peace Documents On This Site
I have placed on my links page a number of links to democratic peace studies so limited to war. My Q and A on Democracy and War also (only for the purposes of this Q & A) confines the democratic peace to war, as does some of my research documents, such as "Libertarianism and International Violence".
Although this understanding of the democratic peace is extremely important--after all it implies the end of war--I believe that focusing only on this version is fundamentally misleading. It is as though we had scientifically established that a drug generally cured or minimized all cancer, called it a "cancer cure," while only focusing the drug on lung cancer in our medical advice.
This analogy is not strained, for democracies have not only not made war on each other, but they also have, by far, the least foreign violence, domestic collective violence, and democide (a much greater killer than war by several orders of magnitude). That is, democracy is a general cure for political or collective violence of any kind--it is a method of nonviolence. This is truly a democratic peace. I call this understanding of the democratic peace, which is supported by the theory, evidence, and analyses on this web site, the general version. See, for example, The Miracle That Is Freedom and Power Kills.
To be clear, then:
Within this general understanding of the democratic peace, democracy in its modern 20th Century version, means regular elections for the most powerful government positions, competitive political parties, near universal franchise, secret balloting, and civil liberties and political rights (human rights).
Research on pre-20th Century war within the war version of the democratic peace, however, has necessarily required a relaxation of the definition of democracy to mean periodic, competitive elections, that the powerful can be so kicked out of power, and that a body of citizens hold equal rights regardless of class or status (see, for example, the research by the historian Spencer R. Weart, Never At War, New Haven: Yale University Press, 1998). Such research by Weart and others still found that as far back in history as classical Greece, democracies rarely, if at all (Weart concludes, "not at all,") made war on each other. The documentation of all this, an absolute requirement if one is going to accept that there is a democratic peace, limited to war or generally conceived, is on this web site in actual research documents or in references to the supporting scientific and scholarly works of others, as listed in the sidebar.