Introduction

This is, of course, one of the oldest debates in the discipline of International Relations. Michael Doyle (1983a, 1983b) brought the issue back to the Englishlanguage debate in the early 1980s, one decade after Ernst-Otto Czempiel (1972, 1981) did the same in Germany, drawing on a much older theoretical tradition dating back to Immanuel Kant. To summarize the accumulated insights on the relationship between democracy and war we need no more than four statements: 1) democracies almost never fight wars against each other; 2) democracies appear to enter into military disputes and war slightly less frequently than other political systems, but not very much so; 3) democracies thus fight wars almost as frequently as others; 4) democracies are more likely to win the wars they fight than to lose them (Russett and Oneal 2001; Huth and Allee 2002; for a critical overview Müller and Wolff 2006).