Operation Nasr

Operation Nasr also known as Operation Hoveyzeh, fought in early January 1981, was a major battle of the Iran–Iraq War. It was the biggest tank battle of the Iran–Iraq War. Three Iranian armored regiments advanced towards Iraqi forces that had invaded Iranian territory between the cities of Ahvaz, Susangerd and Dezful. The Iraqi forces were alerted to this movement and feigned a withdrawal. The Iraqis formed three armored brigades into a three-sided box ambush. The Iranians blundered into the ambush and the two tank forces battled for four days in a sea of mud. The Iranians withdrew, leaving many destroyed and disabled tanks stuck in the mud, or, because of logistical misplanning, had run out of fuel and ammunition. The condition of the terrain prevented a clean break from the battle and did not allow the Iraqi forces to pursue what was left of the Iranians en force. On 22 September 1980, Iraqi military forces under the command of Saddam Hussein invaded Iran. Iran, which had been weakened drastically by revolution, were caught off-guard. However, their air force (itself weakened by sanctions and purges) managed to hit numerous Iraqi military and industrial targets, damaging the Iraqi military and economy. Iraq's invasion slowed drastically, and they became bogged down fighting Iranian paramilitary forces in urban actions such as the First Battle of Khorramshahr. By November, the Iraqi invasion force had ground to a halt, and Iran's air force had largely defeated its Iraqi counterpart. Iraq's navy also suffered destruction (Operation Morvarid). Nevertheless, Iran lacked the strength to drive the Iraqis out immediately. Being under American sanctions, the Iranians could not get spare parts for much of their military equipment and had to use it sparingly. While Iranian paramilitaries and irregulars had slowed the Iraqi drive, it took over three months for Iran to deploy its military to the region.