From Wikipedia: "A cargo cult is a millenarian belief system in which adherents perform rituals which they believe will cause a more technologically advanced society to deliver goods. These cults were first described in Melanesia in the wake of contact with allied military forces during the Second World War.
Isolated and primitive island cultures that were lacking technology found soldiers and supplies arriving in large numbers, often by airdrop. The soldiers would trade with the islanders. After the war, the soldiers departed. Cargo cults arose, attempting to imitate the behaviors of the soldiers, thinking that this would cause the soldiers and their cargo to return. Some cult behaviors involved mimicking the day-to-day activities and dress styles of soldiers, such as performing parade ground drills with wooden or salvaged rifles."