I was reading up on the Iranian Hostage Crisis of 1979, and I read that the Ayatollah Khomeini had proposed a simultaneous siege of both the American and Soviet embassies in Tehran. IOTL, they only besieged and took hostages from the American embassy, but what if they simultaneously did so at the Soviet embassy as well? Would the Soviets go as far as invading Iran? As tempting as the thought of a joint American-Soviet invasion during the middle of the Cold War is, I can't see U.S. President Jimmy Carter ordering an invasion of Iran, unless we go back and have Ronald Reagan elected President in 1976.