The Vendikans were the inhabitants of the planet Vendikar in the Alpha Quadrant. This planet was a colony of Eminiar VII founded prior to the 18th century when war broke out between the two worlds.
Upon destroying the Eminian's computer, James T. Kirk imagined that the Vendikans would assume that they'd broken their agreement and planned to fight with real weapons. He further suggested that this would undoubtedly lead to the Vendikans striking first with their weapons, leading to a series of retaliatory attacks if the Eminians didn't offer peace first. (TOS: "A Taste of Armageddon")