Deception is as old as war itself and is a core part of modern doctrine. In Roman times, Spartacus tied weapons and armor to stakes, with fires lit around the camp to trick Roman sentries into thinking his entire army remained in place while he slipped away. The Allies built a whole fake army led by General Patton in WWII to deceive the Germans about where the D-Day landings would come. Today, deception and decoys are key components for protecting aircraft on the ground, as other defenses are not expected to be sufficient.