Russia seized Crimea by force, intervened militarily in Eastern Ukraine, and has shown no sign of stopping its aggression. The U.S. wants to deter Russian aggression but has been unable to find the right formula, especially when faced with fiscal constraints and other demands. Imperial Roman systems of deterrence, conventional deterrence theory, and examples of U.S. deterrence during the Cold War all provide insight into the current U.S. predicament in Europe. The U.S. must deter against both Russian conventional attacks and its so-called hybrid war. In order to do so, the U.S. should station a Joint Task Force-capable division headquarters, additional enablers, two additional armored brigade combat teams, and additional equipment in Europe to deter Russia through denial. Combined with effective diplomacy and deliberate communication, clear when required, vague when necessary, the U.S. will deter Russian aggression while maintaining a free and friendly Europe in furtherance of U.S. interests.