No. 6: Caracas, Venezuela The so-called malandros -- gangs of young men who spar over turf and the right to push drugs -- have made the Venezuelan capital a virtual war zone. In 2011, Caracas witnessed 3,164 homicides -- a staggering figure just shy of the total number of coalition fatalities in Afghanistan during the entire 10-year conflict in that country. Venezuelan officials have been accused of fudging murder statistics, and the actual number of homicides is likely much higher than the reported figure. To make matters worse, up to 90 percent of murders in Venezuela go unsolved. It's no surprise, then, that the rampant violence proved to be the primary issue in the Venezuelan presidential campaign with Henrique Capriles Radonski blasting President Hugo Chávez for failing to stem the bloodshed. (Since Chávez's election in 1998, the murder rate in Venezuela has doubled.) Experts say that easy access to guns, a culture of violence among young men, and a lack of police and prosecutors have combined to create a perfect storm of lawlessness and a homicide rate of 99 murders per every 100,000 residents. Above, a young man on a motorcycle brandishes his handgun during clashes between pro- and anti-Chávez university students before a march toward Venezuela's Supreme Electoral Tribunal in 2007. The clashes left one person dead and six others wounded.