<P> The Carter Doctrine was a policy proclaimed by President of the United States Jimmy Carter in his State of the Union Address on January 23, 1980, which stated that the United States would use military force if necessary to defend its national interests in the Persian Gulf . </P> <P> It was a response to the Soviet Union's intervention in Afghanistan in 1979, and was intended to deter the Soviet Union--the United States' Cold War adversary--from seeking hegemony in the Persian Gulf region . </P>

What doctrine called persian gulf oil a vital us interest to be defended by any means necessary