Editing Democratic peace theory (section)

===Defining war===
Quantitative research on international wars usually defines war as a military conflict with more than 1000 killed in battle in one year. This is the definition used in the [[Correlates of War|Correlates of War Project]] which has also supplied the data for many studies on war. It turns out that most of the military conflicts in question fall clearly above or below this threshold.{{sfn|Ray|1995|p=103}}

Some researchers have used different definitions. For example, Weart defines war as more than 200 battle deaths.{{sfn|Weart|1998}} Russett, when looking at Ancient Greece, only requires some real battle engagement, involving on both sides forces under state authorization.{{sfn|Russett|1993|p=50}}

[[Militarized Interstate Dispute]]s (MIDs), in the Correlates of War Project classification, are lesser conflicts than wars. Such a conflict may be no more than military display of force with no battle deaths. MIDs and wars together are "militarized interstate conflicts" or MICs. MIDs include the conflicts that precede a war; so the difference between MIDs and MICs may be less than it appears.{{Citation needed|date=October 2023}}

[[Statistical analysis]] and concerns about [[Degrees of freedom (statistics)|degrees of freedom]] are the primary reasons for using MID's instead of actual wars. Wars are relatively rare. An average ratio of 30 MIDs to one war provides a richer statistical environment for analysis.{{sfn|Mousseau|Shi|1999}}