The UK occupied Iran during World War II and began to take home Iran’s natural resources, especially its oil! In the 1950s, the people of Iran resented the Europeans robbing them of their natural resources and they wanted to nationalize all of the oil companies that were controlled by the British. Then the British wrote a letter to the government of Iran saying that if they dared to nationalize the British-registered oil companies in Iran that Iran would be paying a heavy price!