ABSTRACT
Since the classic Liberals proposed republican governance of states as a foundation for a “perpetual peace,” a plethora of empirically minded scholars have investigated this claim. Almost without exception, they have found little support at the monadic (state) level of analysis and strong support at the dyadic (pairs of states) level: although democratic countries are just as likely as non-democracies to participate in conflicts, they do not fight each other. The classic theory for the Liberal peace, however, includes a systemic dimension. That is, a global political system is expected to become more peaceful as it exhibits the characteristics and practices of democratic republicanism.
