The Iraqi invasion ordered by Saddam Hussein against Iran, began on September 22, 1980. Its origins lie in the long Arab-Persian animosity and regional rivalries; in particular, Iraqi Hussein wanted to annex the region of Shatt al-Arab.
The surprise invasion of Iraq to Iran produced immediate gains that took control of the Iranian border cities
Saddam Hussein believed to have the support of the Sunni Arab Iranians who were not happy with the Shiite regime of the ayatollahs in Iran since 1979, when they overthrew the Shah Mohammad Reza Pahlavi regime. Contrary to the thinking and wishes of Hussein, all those Iranian Sunni Muslims volunteered to support the defense of their homeland.
Iran Air superiority was a decisive factor in the confrontation, with the help of the United States.In June 1982, the withdrawal of Iraqi troops began because they were demoralized and aware of the loss. Saddam Hussein ordered his troops back to the starting point.
Ayatollah Khomeini refused to make peace and order to invade Iraq, in the same month of June 1982. Saddam's Arab friends offered US $ 70 million in compensation to Iran, but Ayatollah refused the offer and insisted to remove Saddam Hussein from power in Iraq and replace it with a Shiite Islamic republic.
Iran made the mistake of putting human shields of thousands of children escorted by the Iranian army, but they were all massacred in July 1982. Iraq was about to lose access to the Persian Gulf.
Aid changed when the Iranians began to destroy Iraki oil tankers which caused the US entry into the war against Iran and saved the life of Saddam Hussein and the Iraqi entire country.
In July 1988, after expelling Iran from Iraqi territory, the United Nations intervened as conciliators. On August 1988 a peace agreement was achieved.