Saddam had another hole card: the Iranian Arab minority. He figured two could play the destabilization game. If Iran started stirring up the Shia majority in Iraq, he'd just return the favor by getting the Arabs in Khuzestan (Western Iran) excited about seceding.
So on September 22, 1980, Saddam launched the biggest surprise attack since the Egyptian thrust into Sinai in 1973.
Saddam had the Arab-Israeli wars in mind, too. He was especially thinking about the Israelis' brilliant preemptive attack on the Arab air forces in the first hours of the 1967 war. He sent his MIG 21s and 23s to destroy Iran's F-4s and F-14s on the ground. But he didn't have Israeli pilots, SA munitions, or intelligence. The F-4s were in reinforced bunkers, the MIGs couldn't carry enough of a bombload to finish off Iran's big airfields, and a few hours after the attack, Iran had F-4s in the air, attacking the Iraqi armor columns. Just like Stalin after the Nazis attacked, Khomeini had to release dozens of pilots from death-row cells, shove instant rehabilitation and pardon certificates into their hands, and beg them to get into the cockpits and win one for the Imam.
The Iraqi ground attacks went pretty well in some sectors, not so great in others. It was a long front, from Kurdistan to the Persian Gulf. Saddam's army was built on the Soviet model, and they were good at the stuff the Soviets did well, like massed artillery fire and coordinated armor attack. But there was one bit of really bad news for the Iraqis: the Arabs in western Iran didn't revolt on cue. In fact most of them were loyal, fighting with the Persians against the invaders. (Like I've said before, never trust any plan that says "and then the natives will welcome our troops with open arms," no matter whether it's Saddam or that asshole Perle saying it.) Iraq took the Shatt-al-Arab, the key waterway in the delta, and grabbed half of Abadan, the most important oil town along the border. Then the attack bogged down.
The Iranians had some basic advantages. For one thing, a much bigger population than Iraq. And their morale was good from the start. There's nothing a Shiite likes better than sacrifice, and here was a case where you could give your life and save the homeland. The boys came running. Lots of them even brought their own burial shrouds with them -- couldn't wait to get into that once-and-for-all nightie, I guess.
The Iraqis started to flinch. They liked it when they were roaring over Iranian villages in their T-55s, but house-to-house fighting against crazy Shias in death shrouds isn't most people's idea of a good time. The Iranians noticed something that really got their blood up: the Iraqis were decent soldiers, but they didn't like dying.
By November 1980, the Iraqis were stalled all along the border and the Iranians were getting excited. All those "students" who ditched their homework to hassle American diplomats had a new enemy to fight. The saps all joined up and headed for the front.
The Iranians had three separate armies: the regular army, the Revolutionary Guards, and the Militia. They competed with each other, and there was the usual interservice crap, but all three wanted to fight. The regulars wanted to clear their names, the Revolutionary Guards wanted to get their 64 virgin concubines by dying ASAP, and the militia wanted to defend their homes.
The key word is "defend." Defending and attacking are whole different ballgames. If you're going to attack, you need highly trained troops, but if you're only asking your troops to defend you can sometimes get a good performance out of amateurs. The Iranians couldn't match the Iraqi armor, but they had more guts and initiative in small-unit engagements. By the end of 1981 Iran had pushed the Iraqis away from Abadan. From then on, the Iraqis were on the defensive. They dug in their tanks, a dumb, coward's move that took away their mobility and showed how plain scared they were.