Dunnigan is a specialist in war games and Martel a RAND analyst. Their breezy book surveys 200 years of wars that happened and those that didn't. Its conclusions are reassuringly commonsensical: very large wars are difficult to get started, hence rare (only four in 200 years); ignorance of the enemy makes war more likely, as does ignorance of the possibility of war; the military usually recommends against military solutions; and nuclear weapons seem to have prevented major wars. Domke's data base is similar, though his purposes are more explicitly theoretical: for instance, does "interdependence" make war less likely? It does seem to; trading nations have been less likely to go to war.