sentences:  This operation, coupled with Operation Tariq-ol-Qods, and Operation Fath-ol-Mobin, succeeded in evicting Iraqi troops from southern Iran and gave Iran the momentum.On September 22, 1980, because of his desire that Iraq should have complete dominance over the Shatt al-Arab (or the Arvand Rūd) waterway, Iraqi President Saddam Hussein declared war against Iran and launched a land invasion of southern Iran, although operations did occur elsewhere on the Iran–Iraq border.After achieving successes due to the post-Revolution military and political chaos in Iran, Saddam Hussein ordered that the Iraqi troops "dig-in" on the front line.