The Carter Doctrine was issued in the State of the Union Address on January 23 1980 by President Jimmy Carter. Responding to the Soviet Invasion of Afghanistan that had recently taken place, the President stated:

An attempt by an 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.

This policy thus warned the Soviets away from Iran, which had just had a revolution, and at the time was holding hostages in the United States Embassy, and Iraq.