Democracies are less likely to fight because during diplomatic talks they can draw on their domestic values that are rules on ‘how to collaborate without giving up autonomy’. Autocratic cultures most fundamental rule is ‘who is charge’ and then establishing the hierarchy of where everyone else fits. So you are always more likely to end up in stalemate or conflict when an autocracy is one of the negotiating parties because of a higher likelihood they might want to force the issue that they are in charge.