SINCE AUGUST the Iraqis have launched attack after air attack against the huge Iranian oil complex at Kharg Island. But reports of near-total destruction zhould be viewed with skepticism. During World War II it took weeks of near-constant B-24 bomber raids to knock out the great Axis refinery complex at Ploesti. A dozen or so Iraqi jets bombing from 20,000 feet are not going to do the job quickly.

Intended to bomb Iran to the peace table, the Iraqi air strikes are more revealing as a sign of their frustration with a war that cannot be won on the ground.

The Iran-Iraq war now is one of the longest of the 20th century. As in World War I, both sides have the weapons to inflict heavy casualties, but neither has the strength -- because of its own peculiar weakness -- to deliver a knockout blow.

Also, neither side is capable of effective and sustained offensive action, which requires the fluid tactics that come from decentralized authority and well-trained troops. Good second lieutenants are more important than dictators; competent troops count more than religious ardor.

It has been more than five years since Saddam Hussein, president of Iraq, launched an invasion to seize the oil-rich Iranian province of Khuzestan. The numbers were clearly in his favor: 12 Iraqi divisions took on four weak Iranian divisions spread along an 800-mile front.

What was supposed to have been a quick and easy campaign went badly from the beginning. The Iraqis expected to find an Iranian army demoralized by revolutionary purges. They met three armies instead: a regular army eager to erase the stigma of its long association with the shah, the Pasdaran or "Revolutionary Guards," and the Baseeji, Khomeini's "Army of 20 Million."

Revolutionary zeal more than compensated for whatever the Pasdaran and Baseeji troops lacked in equipment. Early reports described Pasdaran troops dressed in burial shrouds, standing firm in the face of overwhelming Iraqi numbers.

Although the Iraqi battalions were flush with the best equipment petrodollars could buy, their advantages were frittered away by wretched battlefield leadership. "Iraqi soldiers are tigers led by a pack of jackasses," sniffed one British officer.

Initial Iraqi advances of 50 miles a day slowed in the block-by-block fighting for the city of Khorramshahr. Within a few months the overextended Iraqis were reduced to a defensive campaign. Although over 20 Iraqi officers were executed to discourage retreats, by June, 1982 Iranian forces had ejected the invader.

What began as a contest of maneuver, of strike and counterthrust, has since devolved into a bloody war of attrition. A succession of Iranian attacks with macho names like "Undeniable Victory," "New Dawn" and the more sinister "Operation Jerusalem" have accomplished almost nothing but to add to Iran's long list of war dead, variously estimated between 150,000 and 200,000. The Baseeji have suffered especially frightful losses spearheading attacks through Iraqi minefields; a survivor returning to Teheran is called a "living martyr."

Iraq will not admit its own losses, but the presence of thousands of Egyptian, Jordanian and Sudanese "volunteers" suggests that native ranks have been thinned greatly.

But the reasons for the stalemate go beyond Khomeini's determination to march two million of his Shi'ite followers through Iraq to Jerusalem, as he has threatened repeatedly. Faith alone will not carry Khomeini's ragtag legii today. His big guns can only avert disaster, and the very best he can hope for is a fretful and bitter peace.