Siege of Basra

The Siege of Basra, code-named Operation Karbala-5, was an offensive operation carried out by Iran in an effort to capture the Iraqi port city of Basra in early 1987. This battle, known for its extensive casualties and ferocious conditions, was the biggest battle of the war and proved to be the beginning of the end of the Iran–Iraq War. The Iranians failed to reach their objective.

The battle
Copied content from Iran–Iraq War; see that page's history for attribution

Operation Karbala-5 began midnight 8 January 1987, when a strike force of 35,000 Revolutionary Guards infantrymen crossed Fish Lake, while four Iranian divisions attacked at the southern shore of the lake, overrunning the Iraqi forces and capturing Duaiji, an irrigation canal. They used their bridgehead at Duaiji as a springboard to recapture the Iranian town of Shalamcheh. Between 9–10 January, the Iranians broke through the first and second defense lines of Basra south of the Fish Lake with tanks. The Iranians rapidly reinforced their forces with 60,000 troops and began to clear the remaining Iraqis in the area.

As early as 9 January, the Iraqis began a counter-attack, supported by newer Su-25 and Mig-29 aircraft and by 10 January the Iraqis were throwing every available heavy weapon in a bid to eject the Iranians. Despite being outnumbered 10–1 in the air, Iran's air defenses downed many Iraqi aircraft (50–60 jets total; 10% of Iraq's air force), allowing Iran to provide close air support with their smaller air force, which also proved superior in dogfighting, causing the Iraqis to temporarily stop providing their troops air support. Iraqi tanks floundered in the marshland and were defeated by Cobra helicopters and TOW missile-equipped anti-tank commandos. Later in the battle, after their ground forces took heavy losses due to the lack of air support, the Iraqi aircraft came back to the battlefield once again, facing their Iranian counterparts.

Despite superior Iranian infantry tactics, it was the depth of the Iraqi defences that prevented the Iranians from achieving a victory. On 19–24 January, Iran launched another infantry offensive, breaking the third line and driving the Iraqis across the Jasim river. The battle became a contest of which side could bring more reinforcements. By 29 January, the Iranians launched a new attack from the west of the Jasim river, breaking through the fourth line. They were within 12 km of the city. At this point, the battle became a stalemate. Iranian TV broadcast footage of the outskirts of Basra but the Iranians pushed no further. Iranian losses were so severe that Iraq took the offensive and pushed them back to their original positions. The fighting continued and 30,000 Iranians still held positions around Fish Lake. The battle bogged down into a trench war, where neither side could displace the other. Iran attacked several more times but without success. Karbala-5 officially ended by the end of February but the fighting and siege of Basra continued.

Among those killed was Iranian commander Hossein Kharrazi. Possibly 65,000 Iranians and 20,000 Iraqis became casualties because of Operation Karbala-5. Basra was largely destroyed, and Iraq's army had taken many material losses. The fighting during this operation was the heaviest and bloodiest during the war, with the area around Shalamcheh becoming known as the "Somme of the Iran-Iraq War". At one point, the situation had declined to the point that Saddam ordered several of his officers to be executed. With Iranian aircraft fighting at Basra, the Iraqis bombed Iranian supply routes with chemical weapons, as well as Iranian cities with conventional bombs, including Tehran, Isfahan and Qom. It is believed that around 3,000 Iranian civilians were killed in these attacks. Iran retaliated by firing eleven long-range missiles at Iraqi cities, inflicting heavy casualties among civilians and killing at least 300.