The early liberals recognized that peace and freedom presupposed a working system of controls and rules to structure societal competition and contain it within peaceful bounds; they acknowledged that these rules needed to be upheld, in extremis, by the coercive powers of the state (Paris, 2006, p. 438).
Paris is a political scientist and so, as is normal for that discipline, starts with the assumption that state violence is legitimate, especially in defense of--what? Civil liberties? This assumption is pervasive, of course, and is viewed by most as some sort of eternal verity. On the other hand, the challenge to nonviolent researchers and practitioners is to show how to move beyond the endless evocation of Hobbes, whose analysis of life as "nasty, brutish and short" might have been his thought upon looking in the mirror on a bad hair day, but perhaps we can open some vistas beyond such lugubrious commencements.
It is true, certainly, that democracies play well with each other more often than do other sorts of regimes.
Democratic dyads are much less likely than nondemocratic dyads to engage in any kind of militarized dispute (Kriesberg, 2007, p. 140).
But--and Paris does point out this piece well--there are more instances of failed states and attempts to (Oxymoron Alert!) "install democracy" than ever, so the piece of the liberal peace that Kriesberg notes (largely from research of Russett and others) is important, but the real questions go deeply into globalizing justice, don't they? After all, as LaDuke (2002) points out, invasion of extractive and exploitative economies kills indigenous lifeways, so the starting point in the era of Kant is not the starting point we see today. It is tougher now; only nonviolence can rise to this challenge.
Kriesberg, L. (2007). Constructive conflicts: From escalation to resolution. Lanham MD: Rowman & Littlefield.
LaDuke, Winona (2002). The Winona LaDuke reader: A collection of essential writings. Stillwater MN: Voyageur Press.
PARIS, R. (2006). Bringing the Leviathan Back In: Classical Versus Contemporary Studies of the Liberal Peace. International Studies Review, 8(3), 425-440. doi:10.1111/j.1468-2486.2006.00601.x
Russett, Bruce (1993). Grasping the democratic peace: Principles for a post-cold war world. Princeton, NJ: Princeton University Press.