Zealous but weary soldiers push Iran's war crusade against Iraq

''I participated in all the offensives (in the war with Iraq), was wounded three times, but God didn't want to take me to heaven,'' a young Iranian revolutionary guard says.

Asked about his reasons for returning to the front, he confesses: ''I want to go to Karbala in Iraq to pray on Imam Hossein's grave.'' (Hossein is the prophet Muhammad's grandson.)

Religion is the driving force for Iranian fighters. In Tehran the war is portrayed as a crusade against the unbelievers.

The Iranians also say they are fighting against the Soviet Union and France, which are Iraq's main arms suppliers. They accuse the United States of supporting the Iraqi regime by granting it loans at low interest rates.

After Iraq started the war in 1980, Iran launched its first drive into Iraq during the summer of 1982. Near the city of Basra, Iranians and Iraqis are said to occupy small pockets of each other's territory.

Farther north the Iranians have pushed a few miles toward the Iraqi town of Mandali. West of the Iranian town of Mehran they have taken strategic hills from which they could launch an offensive to the Iraqi plain.

During a recent offensive, Iran's revolutionary guards and soldiers took control of Kurdish areas that had been occupied by internal opponents since the 1979revolution.

They proceeded into Iraq and occupied the entire Chilere Salient. They are less than a mile from the Iraqi town of Penjwin.

''We are divided in squads, each of them with a special task,'' explains a revolutionary guard. ''The general staff fixes the penetration axis. We then clear mines with detectors on narrow strips of land.

''We have to search for certain types of mines with our hands. There are also spots where the only way is to walk on the field. We have volunteers for that job.''

When an offensive is launched, bulldozers level the previously cleared areas and fill up the trenches the Iraqis had dug. Then come the infantry and the armored vehicles.

''Iraqi combat helicopters are dangerous,'' says another guard, ''but the worst is machinegun fire.''

''We are not afraid,'' he adds proudly. ''We trust in God and we move forward.''

''It is true,'' says a colleague. ''There are kids on the front line. But they haven't been enrolled by force. Recruiting officers always try to dissuade them and at least ask for a written permission from their parents.'' A man breaks in on our conversation.

''Those kids are more mature than any of us,'' he says. Iranians say toppling the Iraqi regime is their aim. Three weeks ago a group of Iraqi religious leaders living in Tehran organized a conference to expose ''Saddam's crimes'' (President Saddam Hussein of Iraq) and explain how they intend to rule Iraq after its Islamic revolution.

''We believe some of our leaders . . . who have a great religious knowledge and whom we call mojtahed . . . receive orders from Mahdi, the hidden Imam,'' a young militant says.

Shiite Muslims believe in the existence of 12 Imams who ruled the community of the believers after the death of the prophet Muhammad. Mahdi, the last one, ''disappeared'' in the year 873. His ''return'' to establish the rule of God on earth is ''expected'' by the believers.

These Iraqis have set up a parliament in exile that draws its support from among the 100,000 Iraqi Shiite Muslims of Iranian origin who were expelled from Iraq and some of the 50,000 Iraqi prisoners of war in Iran.

Observers in Tehran have doubts about the political future of this parliament in exile. ''They lack a serious leader,'' a diplomat says.

''We took the ideological decision that we would get rid of Saddam Hussein,'' an Iranian says, ''but we realize it will be difficult. Sometimes we are tempted to be conciliating, but when the Iraqis bombard our cities, killing hundreds of civilians, they force us to continue the war.''

From the beginning of the conflict the Iraqis tried to push Iranian civilian populations out of the war zones by firing missiles at civilian neighborhoods. Now they use this technique to retaliate after each Iranian offensive.

''These are Soviet-made SCUD and Frog missiles,'' a Western diplomat says. ''When they are targeted at brick houses, the result is terrible.''

Iranian television regularly shows pictures of poor villagers searching the ruins of their homes for the bodies of their relatives. After each missile attack, the government sends messages to international organizations. In June, 1983 a United Nations Security Council investigation team concluded that Iranian civilian areas had suffered more from the war than similiar areas in Iraq.

In late December President Hussein warned that his country might resort to ''new weapons'' in its war against Iran. This was an allusion to the five Super Etendard jets equipped with Exocet missiles that the Iraqi Air Force recently bought from the French.

The Iranians have warned repeatedly that they would respond to any attack against their oil installations by blockading the Strait of Hormuz.

Jordanian diplomatic sources in Europe say the French persuaded the Iraqis to use the Super Etendards only in case of an all-out Iranian ground offensive. At present the Iranians keep the bulk of their air force to protect their oil terminals and to escort merchant ships sailing their ports in the northern part of the Gulf.

Despite the tough official rhetoric and the religious fervor brought to the fighting, many Iranian revolutionaries are eager to see the war over.

''This war,'' says one Iranian, ''requires unity among the people which at this stage of the revolution means political immobility. We have domestic issues that are presently rotting. This is very dangerous for the regime.''