For centuries, fog, smoke and dark of night have provided combatants a strategic advantage. Keeping out of sight of your enemy has allowed armies to move personnel and equipment, prepare ambushes and, when necessary, beat feet out of an area.
During the Revolutionary War, General Washington used the cover of night to move his troops across the Delaware River for an early morning attack against Hessian mercenaries. The element of surprise resulted in only nine casualties for the Americans and more than 10 times that many for the enemy, not including the thousand or so captured and all the enemy equipment seized.
Sun Tzu wrote that the art of war is the art of deception, and that has remained true thought history. Inflatable and dummy tanks as well as “paradummies” (airborne mannequins) were used to deceive enemy forces during World War II by both sides. During the Vietnam War, enemy troops took great advantage of tunnels and jungle cover to hide their movements. Today, insurgents bury and disguise improvised explosive devices.
In domestic areas, criminals are also adept at using cover and deception. One sad trend is for criminals to ambush police officers, again using the dark of night to their advantage. New technology, however, is becoming increasingly useful at revealing what was hidden and continues to improve.