The conflict between Iraq and Iran raged Sunday at unprecedented levels of intensity. Both sides reported air and missile strikes on towns and cities, more attacks on shipping in the Persian Gulf, and ferocious battles on the ground as Iranian forces continued their efforts to cross the Tigris River in southern Iraq.
Iraq introduced a new dimension to the 41/2-year-old war Sunday by declaring that all Iranian airspace will be a war zone starting Tuesday evening. Iraq warned international airlines to steer clear or risk having their airliners shot down. A number of airlines have already decided to suspend flights into both Iran and Iraq.
If the Iranians can consolidate positions west of the Tigris River, they will have cut the main highway linking Baghdad with Basra. There are several other routes between Basra and the capital, and the Iranians would still have a great deal of ground to cover if their aim is to isolate the Basra area from the rest of the country.
But if they can hold positions on the main highway alongside the Tigris, they will have achieved their most significant penetration to date, disconnecting the Iraqi front line for the first time.
Given Iraq's well-organized defenses and daunting air power, the Iranians must have paid a terrible price for their advance.
But for the Iraqis, it must be deeply worrying that, five days after the campaign began and despite Iraq's claims that it had turned the tide, the Iranians were in a position to launch what by Iraq's admission was a major thrust across the Tigris.
The Iranians would of course remain vulnerable to continuing Iraqi efforts to oust them from the north and south, and to the full fury of Iraq's superior air power. But for the time being, Iran's two main advantages in the war -- its greater manpower and its forces' willingness to risk life and limb -- appear to have paid off on the battlefield.
Iraq, meanwhile, has been going all out to make the most of its superior strike power.
In the past two weeks, Iraqi warplanes have raided more than a score of Iranian cities, while long-range missiles have wrought havoc in other centers. Iran has given civilian casualty figures of hundreds killed and thousands injured.
Iran's ability to hit back in kind is seriously restricted. Iranian field artillery has pounded urban areas, particularly Basra, but the severity of casualties and damage that can be inflicted by such bombardments cannot compare with the devastation caused by heavy bombs and missiles.
Iranian warplanes have made several efforts to attack Iranian cities, including one strafing raid on the outskirts of Baghdad, but the Iraqis admitted no serious casualties or damage.
Clearly, the balance in these exchanges is strongly in Iraq's favor. The Iraqis insist they will only halt the campaign if Tehran agrees to negotiate the wider peace it has so far refused to contemplate.
Before nightfall Sunday the Iraqis had reported that their warplanes had carried out raids on seven Iranian cities, including Tehran -- the third strike on the Iranian capital in less than a week.
The Iranians confirmed the attempt to bombard Tehran, but said their antiaircraft defenses had driven off a single Iraqi jet, which dumped its bombs outside the city.
Tehran also reported further Iraqi long-range missile attacks on two more cities, Dezful and Andimeshk, in western Iran.
Over the weekend, both sides reported that Iraq's major port city, Basra, as well as other towns near the border, came under frequent artillery bombardment from Iranian guns on the front lines.
On Saturday, Iran said it had fired a single long-range missile at the Iraqi capital of Baghdad, though the Iraqis said that a big explosion in a residential quarter of the city had been caused by a car-bomb, which demolished a building, leaving a number of casualties.
In the tanker war, Iraq claimed yesterday its warplanes had hit two ``large naval targets'' -- usually Iraqi military parlance for oil tankers -- near Iran's main oil terminal at Kharg Island. Shipping sources in the Gulf confirmed that at least one ship in that area, identified as the Iranian supply ship Youssef, had been hit.
A Liberian-registered oil supertanker, the Caribbean Breeze, was meanwhile set on fire in the Gulf when it was rocketed by warplanes, which were believed to be Iranian.
Tehran has never claimed responsibility for any such strikes, but is widely believed to see them as a way of responding to Iraq's campaign to disrupt Iran's oil exports. Iraq has attacked ships calling at its terminals and ports.
In recent days, the level of air activity by Iraqi warplanes in particular has been unprecedented during the war. On Saturday, the Iraqis said they carried out no fewer than 13 air raids on towns and cities scattered across hundreds of miles of Iranian territory.
The Iranians confirmed many of the attacks, and said that on that day alone, more than 100 civilians died and hundreds more were injured.
Iraqi pilots have been flying record combat missions over the battlefield, too, as both sides report some of the heaviest fighting -- and carnage -- since the conflict began in September 1980.
On Saturday, Baghdad announced that its warplanes carried out no fewer than 539 missions against Iranian forces battling the Iraqis in the marshlands 40 miles north of Basra, in southern Iraq.
On Friday, Iraq's helicopter gunships had carried out a record 320 sorties in the same area.
Accounts from both sides point to huge numbers of casualties. Late Saturday, an Iraqi military communiqu'e claimed that tens of thousands of Iranians had been killed in an attempt to cross the Tigris River.
Iranian estimates of Iraqi casualties have been more modest. An Iranian spokesman said Saturday that some 2,500 Iraqi soldiers had been killed or injured.
The Iranians initiated their new ground offensive last Monday night, striking out westward toward the Tigris through the inhospitable Hawizeh marshes. Until last Friday, sources with access to satellite intelligence were generally substantiating Iraq's claims that it was making headway in dislodging the Iranians from positions Baghdad admitted they had seized on the western edges of the marsh, close to the Tigris. In that sector the Tigris is at least 12 miles inside Iraq.