"Democratic peace theory" is a political science theory which holds that true democracies rarely go to war with each other, or will make appropriate initiatives and decisions which will effectively prevent such democracies from ever going to war with each other. It is a controversial topic, given that there is also a list of wars between states which, at the time of belligerency, also possessed democratic governance to various extents (among those extents being whether the civilian democratic government held sufficient control over the country’s military institutions).
It’s a nice idea, I’ll admit. Bush, Clinton, Blair (OK, those first three are not good endorsements), and former British governor of Hong Kong Chris Patten have all endorsed the idea that democratic governments don’t battle each other; others have endorsed such alternative ideas as the "economic peace theory", which is used in such scenarios as China/Taiwan and Israel/West Bank.
But after reading about how the Mennonite Central Committee’s members attended a dinner with Ahmadinejad from 2006-2008, the reaction against the MCC by those who were slighted by his outrageous ethnoreligious comments regarding Israel and Jewish people, and how the MCC defended its position by saying that they weren’t coddling the guy, I think that merely being a peace church (as is the case with the Mennonites, Amish, Dukhobors and other small religious groups within the Christian and post-Christian continuum) simply isn’t enough of a guarantor for ensuring that the environment around the church, congregation, temple, synagogue, mosque, etc., will be free, democratic and understanding enough of their varying levels of introversion. Peace churches, as pacifist entities, cannot function for long in societies which are actively belligerent against both their own citizens and their foreign national guests.
Therefore, I think it makes sense for there to be a practice of "democratic pacifism" among and within non-state agencies such as religious congregations, as well as a promotion of both peace and democracy – hand in hand – both at home and abroad. Perhaps this may entail a preference for federal/confederal/supranational governance, perhaps this may entail some degree of proportional representation at the local or regional level, or perhaps this stance may incorporate a long number of other internal features which can turn the religious organization and its congregations into tangible, everyday model institutions for its members.
In the greater scheme of things, I think that a heightening of the idea of democracy as a necessary component for the function of peace must begin in the mind, at home, and at the most frequently-visited institutions which appeal to individual attendees.