Consider what would happen if Carter didn't promulgate the Carter Doctrine and committed the US to intervening in the Persian Gulf area to protect American interests. Here's some information on the Carter Doctrine.
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Announced by President
Jimmy Carter on 24 January 1980, the “Carter Doctrine” extended U.S. containment policy to the
Persian Gulf region. Under pressure from containment advocates, Carter concluded that the 1979
Soviet invasion of
Afghanistan might be the first step in a threat to the Persian Gulf oil resources. Furthermore, with the overthrow of the
shah of
Iran (and seizure of American hostages) by militant Islamic revolutionaries earlier in 1979, the United States had lost its primary military ally in the gulf.
To ensure protection of Middle East oil, Carter declared that the United States would consider any attempt by an outside force (the
Soviet Union) to gain control of the gulf region an assault on U.S. vital interests that would be repelled by military force if necessary. Consequently, Carter expanded military aid to
Saudi Arabia, Egypt, Israel, and
Pakistan, and went beyond surrogate forces to create a U.S. Rapid Deployment Joint Task Force (RDF).
From its new headquarters, the
RDF could call upon 200,000 troops from all services to meet emergencies in the gulf. It also acquired air and naval basing rights at
Diego Garcia, a British
atoll in the Indian Ocean, for positioning more than a dozen preloaded merchant ships to support any initial deployment. Additional basing rights were sought in several East African countries. Many of these were later used in
the Persian Gulf War of 1991.
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As a variation on this theme, you can also consider the possibility that the Carter Doctrine is revoked once the Soviet Union falls and the original premise goes by the boards.