The following key sentence , which was written by Zbigniew Brzezinski , President Carter 's National Security Adviser , concludes the section : Let our position be absolutely clear : An attempt by any outside force to gain control of the Persian Gulf region will be regarded as an assault on the vital interests of the United States of America , and such an assault will be repelled by any means necessary , including military force . Brzezinski modeled the wording on the Truman Doctrine , and insisted for the sentence to be included in the speech " to make it very clear that the Soviets should stay away from the Persian Gulf . " In '' The Prize : The Epic Quest for Oil , Money , and Power '' , author Daniel Yergin notes that the Carter Doctrine " bore striking similarities " to a 1903 British declaration in which British Foreign Secretary Lord Landsdowne warned Russia and Germany that the British would " regard the establishment of a naval base or of a fortified port in the Persian Gulf by any other power as a very grave menace to British interests , and we should certainly resist it with all the means at our disposal . " < ! -- Unsourced image removed : The Persian Gulf region was first proclaimed to be of national interest to the United States during World War II . Petroleum is centrally important to modern armies . The United States , the world 's leading oil producer at the time , supplied most of the oil for the Allied armies . Many American strategists were concerned that the war would dangerously reduce the US 's oil supply and so they sought establishing good relations with Saudi Arabia , a kingdom with large oil reserves . On February 16 , 1943 , US President Franklin Roosevelt said , " the defense of Saudi Arabia is vital to the defense of the United States . " On February 14 , 1945 , while he was returning from the Yalta Conference , Roosevelt met with Saudi Arabian King Ibn Saud on the Great Bitter Lake in the Suez Canal , the first time a US president had visited the Persian Gulf region . During Operation Desert Shield in 1990 , US Defense Secretary Dick Cheney cited the landmark meeting between Roosevelt and Ibn Saud as one of the justifications for sending troops to protect Saudi Arabia 's border
Yalta Conference
Yalta Conference
Carter Doctrine