Proponents of democratic peace theory argue that both electoral and republican forms of democracy are hesitant to engage in armed conflict with other identified democracies. Different advocates of this theory suggest that several factors are responsible for motivating peace between democratic states. Individual theorists maintain "monadic" forms of this theory (democracies are in general more peaceful in their international relations); "dyadic" forms of this theory (democracies do not go to war with other democracies); and "systemic" forms of this theory (more democratic states in the international system makes the international system more peaceful).
In terms of norms and identities, it is hypothesized that democracies are more dovish in their interactions with other democracies, and that democratically elected leaders are more likely to resort to peaceful resolution in disputes (both in domestic politics and international politics). In terms of structural or institutional constraints, it is hypothesized that institutional checks and balances, accountability of leaders to the public, and larger winning coalitions make it harder for democratic leaders to go to war unless there are clearly favorable ratio of benefits to costs.