Bring a gun to a gunfight: armed adversaries and violence across nations.

We use homicide data and the International Crime Victimization Survey to examine the role of firearms in explaining cross-national variation in violence. We suggest that while gun violence begets gun violence, it inhibits the tendency to engage in violence without guns. We attribute the patterns to adversary effects-i.e., the tendency of offenders to take into account the threat posed by their adversaries. Multi-level analyses of victimization data support the hypothesis that living in countries with high rates of gun violence lowers an individual's risk of an unarmed assault and assaults with less lethal weapons. Analyses of aggregate data show that homicide rates and gun violence rates load on a separate underlying factor than other types of violence. The results suggest that a country's homicide rate reflects, to a large extent, the tendency of its offenders to use firearms.