The relationship between the United States and Saudi Arabia is a recurring idea in the book. The relationship dates back to the 1930s, when Standard Oil of California secured oil leases on the land and drilled the first oil well. Saudi Arabia is the world's biggest oil producer and has the largest reserves of oil. Both countries cemented their relationship during World War II, even though at that time the United States used Latin American oil. Over the years, as the United States economy grew, the country become more and more dependent on Middle East oil and particularly Saudi Arabian oil. Saudi Arabia is now the biggest supplier to the United States.