A MAJOR SHIFT in Iran's approach to the hostage question has now been confirmed by Iranian Prime Minister Rajai. Speaking at a news conference, he indicated that Iran has already been essentially satisfied in the matter of its demand for an official American apology -- this had previously been considered perhaps the central hang-up. Instead, he put the emphasis of Iranian concern on the month-old war with Iraq.If the United States were to remove its AWACS air-warning planes from Saudi Arabia, to prevent Jordan from supporting Iraq and to cut back its fleet in the Indian Ocean, he said, Iran would be encouraged to release the hostages.

It is, of course, unthinkable that the United States should jump to satisfy these new Iranian demands, or hints, or whatever they are. The Khomeini regime cannot be allowed to take over the direction of American foreign policy. It is almost too obvious to say. Not just since the Iran-Iraq war but for many months, however, American officials have felt that if the regime in Tehran could place the hostages in a context of the interests of the Iranian state, rather than using them as a pawn in the internal struggles of the Iranian revolution, the prospects for their release would improve. That Mr. Rajai, an Islamic fundamentalist, now approaches the hostages in a national context is notable. His insistence that the Iranian parliament is currently seized of the hostage issue and actually has the authority to deal with it is, if untested, welcome.

Secretary of State Muskie responded yesterday with appropriate care. He observed that Mr. Rajai, in citing the AWACS planes and Jordan, was expressing concern but not establishing new conditions for the hostages' release. Underlining the fact that the United States cannot allow Iran to dictate the terms of American relations with third countries, he said that the administration was pursuing the American national interest in providing Saudi Arabia, "a friend," with strictly defensive equipment and that the administration had done what it could to make clear to Jordan, "a sovereign state," that no nation should act to widen or prolong the war. Whether the United States might resume the supply of spare parts and arms to Iran, Mr. Muskie said, could be raised only, if at all, in a negotiation of a sort that Iran has yet to invite. Meanwhile, he noted, as though to convey to both sides that a negotiated end to the war remains possible, Iraq says its only war aim is to resolve the question of disputed territory.

The administration, it seems, is trying to do what is necessary to reclaim the hostages without tipping excessively toward Iran or Iraq in the war or otherwise impairing the national interest. Mr. Muskie was calm and level-headed in what he said yesterday and that is what it will take.