Earthen tunnels have been used to cross country borders, in military conflicts and to smuggle supplies, people, weapons and drugs. Tunneling is a battle military tactic that goes back more than 2500 years. Earthen tunnels have been dug between Lebanon and Israel, Syria and Israel, Gaza and Israel, Egypt and Gaza, North Korea and South Korea, Cambodia and Vietnam and Mexico and the United States to permit the movement of soldiers, supplies, weapons and drugs under the borders. North Korea, Iraq and Iran used tunnels to hide weapons, including nuclear, and other military equipment and supplies. In the early 2000s, ISIS created many earthen tunnels under Iraqi and Syrian cities for military use. Soil tunnels have often been successfully used by an inferior military force to surprise attack a superior military force.