THE QUESTION NOW is whether events in Afghanistan have overtaken the policy the administration has been applying in Iran since the hostages were seized on Nov. 4.

That policy, one of graduated pressure, made sense while Iran was isolated (not even Moscow supported its seizure of American diplomats) and while the security and integrity of Iran itself were not directly at stake. But Iran is no longer isolated: The Soviet Union, seeking to escape the diplomatic condemnation that its invasion of Afghanistan has reaped, is eagerly putting itself forward as the protector of Iran against American-sponsored pressures, political and economic now and possibly military later. And Iran is not secure: the local Soviet-controlled communist party (Tudeh) has been giving ground and may now be better positioned than any other Iranian political group to capitalize on chaos and fragmentation. The Soviet army, which previously sat only on Iran's northern border, now sits on its eastern border in Afghanistan as well. Iran itself has no army to speak of.

Pre-Afghanistan, it made sense, or so we have felt, that the chief American goal was to win the release of the hostages -- and by so doing to demonstrate American determination. It was in that spirit that the United States first reacted to the Soviet invasion of Afghanistan, treating it as yet one more reason why Iranians should promptly resolve the hostage question: the better to face the danger of Soviet power. Precisely because Afghanistan has made that danger more real, however, the administration may have to rethink its policy and accent as its new priority the preservation of the independence and integrity of Iran. For the disintegration of Iran or its takeover by communists or its invasion by Soviets summoned by those communists would be a disaster of a magnitude surpassing anything that has happened so far, including the kidnapping of the diplomats.

The sanctions came along on the old pre-Afghanistan track. But if the preservation of Iranian independence is accepted as the post-Afghanistan priority, they may have to be reviewed. Iranians can hardly be expected to take seriously American solicitude for their security against a Soviet threat if at the same time the United States is leading a broad campaign to throttle the Iranian-economy. To the extent that such a campaign succeeds, moreover, it may merely soften up Iran more for the communists. Surely there are Iranians with no illusions as to where the true threat to their country lies. But they will have trouble identifying with the United States in a context where the administration is leading a sanctions squeeze. As for the hostages, an American showing of respect for Iran's security might do as much for them -- certainly it would do no less -- as a continued tightening of the screws.

We are talking strictly of the economic sanctions issue. There is no question of returning the shah or of acquiecing in any of those recommended anti-American festivals, called tribunals or whatever, to be conducted by Ayatollah Khomeini. The issue is what will in fact serve American interests. If the administration having charged up the bill sanctions were to back down now, Soviet propagandists -- not to speak of some of Mr. Carter's political rivals -- would have a heyday. The test of policy, however, is not whether it fits past projections, but whether it responds to the real world. Afghanistan is the real world.