The presence of drugged fighters is not unknown in the history of warfare. Yet widespread drug use on the battlefield is now part of protracted conflicts largely fought by nonprofessional combatants that take place in an international system characterized by the process of globalization. From marijuana, khat, hallucinogenic mushrooms, cocaine, heroin, and methamphetamine to looted pharmaceuticals, irregular fighters have found a ready supply of narcotics to consume for a variety of combat purposes. Such consumption has led to unpredictable fighting, the commission of atrocities, and to the prolongation of internal violence. The presence of intoxicated combatants will continue to be a feature of armed conflict and requires a fuller accounting to adequately prepare policymakers and military planners for future conflicts.