MSNBC Morning Joe anchor Mika Brzezinski's father Zbigniew Brzezinski was National Security Advisor to President Carter. He is the one who made the arms for hostage deal with Iran. Reagan was stuck with carrying the plan out.
This was President Carter's Politics Of Revenge against Ayatollah Khomeini who lead to his electorial defeat. Carters change in the U.S. attitude toward Iraq was warmly welcomed in Baghdad. Saddam Hussein had an old score to settle with the Iranians over his southern border. Saddam was lead to believe by Brzezinski that his role as a counter to radical fundamentalist Ayatollah Khomeini in Iran would boost the United States acknowledgment of him as head of the Arab world.
Saddam Hussein made a visit to Amman in 1979, before the Iran–Iraq War, where he met with King Hussein and three agents of the Central Intelligence Agency. Records have American officials meeting only with King Hussein on precisely the same date, noting this "top-secret negotiating session was Brzezinski's idea." Brzezinski was "letting Saddam assume there was a U.S. green light for his invasion of Iran, because there was no explicit red light."
The U.S. acted in an attempt to prevent the confrontation from widening. As a result, the U.S. reacted to Soviet troop movements on the border of Iran by informing the Soviet Union that they would defend Iran in the event of Soviet invasion. The U.S. also acted to defend Saudi Arabia, and lobbied the surrounding states not to become involved in the war. Brzezinski characterizes this recognition of the Middle East as a vital strategic region on a par with Western Europe and the Far East as a fundamental shift in U.S. strategic policy. Carter used the Iran–Iraq War as leverage with which to resolve the Iranian Hostage Crisis. The Carter administration used both "carrots," by agreeing to supply military weapons to Iran upon release of the hostages, and "sticks," by discouraging Israeli military assistance to Iran and suggesting that they might offer military assistance to Iraq if the Iranians did not release the hostages.