From the front of the rule book:
The overriding object is to remain in the game! Each player represents a Superpower with influence over the Leader pieces of his own colour. By manipulating these Leaders, and their Secret Agents, players gain or relinquish power in the countries of K A R K with the purpose of acquiring oil fields. By also acquiring Tankers they seek to maintain a flow of oil/revenue to keep them powerful.
English/French copy of the game with The Armchair Strategist's Introduction to The Game of Nations and a bilingual rule book (English/French)