Iranians pay high price for military drives into Iraq

''Iraq's military situation is so desperate that Saddam Hussein should commit suicide,'' Ayatollah Khomeini declared three months ago.

But ever since, the leader of the Iranian revolution has been more discreet about the war - with good reason.

Although Iran recovered most of its Iraqi-occupied territory this spring, its subsequent offensives into Iraq itself have been much less successful. And their cost has been high - in terms of both casualties and morale. Where once volunteers flocked to fight for their faith and their country, today their numbers are dwindling.

The offensives were themselves the outcome of disagreements and lengthy behind-the-scenes discussions between Iranian leaders.

One faction wanted to take advantage of success in largely expelling Iraqi forces from Iranian territory by signing an immediate peace treaty. The other faction, angered by the continuing Iraqi shelling of the Iranian oil city of Abadan, saw this as evidence that ''no peace is possible without the downfall of (Iraqi President) Saddam Hussein.''

As usual, Khomeini followed the hard-liners. He ordered the troops to go in.

The first (July) drive into Iraq failed to achieve its main objective: the takeover of the Iraqi city of Basra.

The Iraqis mounted a stiff resistance. They let the Iranians come in and then hit them with artillery and helicopter-launched missiles when they were in the midst of huge swamps. Hundreds of Iranian tanks were destroyed. The offensive bogged down near the border.

''It was terrible,'' says an Iranian who recently went to the front. ''Our boys were cut from their supply lines and without serious air protection. They tried to retreat, but thousands were taken prisoners or were killed.''

''It you look at a map,'' a Western diplomat says, ''you see that the Iranians are in a dead-end. Should they succeed in getting out of these swamps, they will have to cross the Shatt al Arab, which in that area is very wide.''

The Iranians are aware of the failure of their July offensive. They don't take journalists to the front line any more. At a recent press conference the chief of the ground forces, Col. Sayad Shirazi, didn't say a word about the situation in the Basra area.

The second offensive into Iraq was launched Sept. 30 across the border some 100 miles northeast of the Iraqi capital of Baghdad. This, too, has been subject to Iraqi counterattacks. [Iraq reported Oct. 6 a huge counteroffensive in the mountains near Mandali.]

And, once again, fierce quarrels are taking place behind the scenes. The mullahs are said to have decided to be more cautious in the future and to try to limit the number of casualties. They have realized that their best supporters are being killed in the war.

Despite - or because of - long TV propaganda programs in which mutilated men explain how they met the Prophet Mohammed while walking on mine fields, the number of volunteers is quickly dropping. Western intelligence sources even report that a revolt occurred in a camp near Ahvaz where Bassidj were waiting to be sent to the front line.

Bassidj are boys in their teens, driven by a deep religious faith, who volunteer to go to the front lines after a very limited training. Bassidj are always doing the ''dirty jobs'' - crossing mine fields or attacking heavily defended Iraqi positions with light weapons.

''As long as the offensives were successful,'' says an observer, ''they agreed to play the game. But after what happened near Basra their enthusiasm has been tempered.''

Massoud Rajavi, who from Paris leads the armed struggle against the Islamic regime, contends that ''there are problems with the Bassidj because those teen-agers have been forced to go to the front.''

The latest Iranian drive near Mandali may have a greater chance of success than the July offensive. But with a part of the Army locked in the Basra area, and with hundreds of soldiers and Revolutionary Guards fighting the Kurdish insurgency and trying to quell rebellious tribes in the area of Shiraz, there are few forces left to sustain a new prolonged offensive.

''We want the war to end very soon,'' says Mohsen Nourbakhsh, governor of Iran's central bank. ''But we strongly believe that if we don't achieve a complete victory, our neighbors will again plot against us. They should realize that Iran is the most powerful country in the Persian Gulf.''

In Tehran, many observers expect the war to last for at least several more months. Members of the government repeat that the war will end after the departure of all the Iraqi soldiers still in Iran, the punishment of aggressors, and the payment of reparations.

Every evening the television broadcasts a song that says ''we are going to the holy city of Karbala.'' Says a diplomat: ''Karbala is deep into Iraq. Going there might take years.''