This paper presents a survey of parliamentary ‘war powers’ based on a comprehensive and detailed review of the degrees and institutional forms of parliamentary involvement in military security policy-making. As our original research project focused on the involvement of European Union (EU) states in the recent Iraq war, we present data for the then 25 member and accession states of the EU as of early 2003. This survey of parliamentary war powers covers the legislative, budgetary, control, communication related and dismissal powers of the respective parliaments relating to the use of military force. Referring to this data, we distinguish five classes of democratic nation-states, ranging from those with ‘very strong’ to those with only ‘very weak’ war powers of the respective national parliament.

This research is linked to the debate on the alleged peacefulness of democracies. In this debate, up to now, democracies have usually been treated as a homogeneous category regardless of whether military security policy-making is under parliamentary control or not. Empirical surveys based on this undifferentiated concept of democracy found that democracies (almost) never wage war against each other, but on average are not significantly less warlike than other states. However, we found that the degree of democratisation, or rather parliamentarisation, of military security policy-making makes a difference: in the case of the Iraq war in 2003 we identified that a pattern of high parliamentary war powers is significantly linked to low war involvement.