There is growing alarm over how drugs empower terrorists, insurgents, militias, and gangs. But by looking back not just years and decades but centuries, Peter Andreas reveals that the drugs-conflict nexus is actually an old story, and that powerful states have been its biggest beneficiaries. pIn his path-breaking emKiller Highem, Andreas shows how six psychoactive drugs-ranging from old to relatively new, mild to potent, licit to illicit, natural to synthetic-have proven to be particularly important war ingredients. This sweeping history tells the story of war from antiquity to the modern age through the lens of alcohol, tobacco, caffeine, opium, amphetamines, and cocaine. Beer and wine drenched ancient and medieval battlefields, and the distilling revolution lubricated the conquest and ethnic cleansing of the New World. Tobacco became globalized through soldiering, with soldiers hooked on smoking and governments hooked on taxing it. Caffeine and opium fueled imperial expansion and war