A SURGE OF heavy fighting seems to have broken out in the long war between Iran and Iraq. It is a salutary reminder that this war, now in its third year, is not sinking into the stalemate that had earlier seemed probable and that the balance between those two armies is anything but stable.

While Iraq started it, the initiative has shifted, and now it's Iran that seems determined to press the attack. The Iraqis, although better armed, are apparently having serious trouble with falling morale. Their troops do not seem eager to get themselves killed in a war that from their viewpoint is increasingly pointless. But martial ardor is running high in revolutionary Iran, and there seems to be no hesitation to throw massed formations against Iraq's modern weapons. As every infantryman has known since 1914, that's a very fast way to lose men. But the attacks continue.

The Iraqis say that Iran's casualties have been running high. Iran says that Iraq is slowly giving ground. It is entirely plausible that both statements are true. If the Iranians can force a breakthrough, it will be more than interesting to see whether they move west toward Baghdad or swing south toward the conservative oil states whose moneybags have been supporting Iraq.

On a not entirely unrelated subject, you have probably seen references to the debate over future oil prices. The forecasts are based on careful econometric studies of demand, production capacity and so forth. Does it not strike you that there may be a factor missing from those tidy computations--a rather large factor? The mullahs have found that oil can be very useful to pay the bills for a holy war, but they do not seem deeply committed to meeting other people's delivery schedules. The course of the war remains totally unpredictable. But you might keep it in mind that the economic forecasts assume a peaceful world. That assumption hardly fits current conditions on the rim of the Persian Gulf.