By the time you read this, Ronald Reagan may be president-elect, but Jimmy Carter will still be president. And whatever unfinished business remains in negotiating the release of the American hostages in Iran will still be his to conduct.

But with a monumental difference: there will be no further incentive for the sort of near-hysterical Republican forebodings of "sellout" and "manipulation" that filled the air in the campaign's last few days. And that, I suspect, is going to give an utterly different cast to the conditions the Carter administration ultimately negotiates for the hostages' release. Indeed, the long denouement of the agonizing hostage experience is also likely to acquire, with the passage of time and a change in perspective, quite a different look.

Consider, as a prime example, the way it looked in the final frenzied hours of the campaign to no less an authority than Henry Kissinger, whose growing proximity to Ronald Reagan made him the archetypical public exponent of the line the Republican candidate was smart enough not to put forth on his own:

The Carter administration's "mishandling" of the hostage crisis from the start, Kissinger told NBC, had given the Iranians "an incentive to raise their terms and to delay." To negotiate on the conditions finally approved by the Iranian Majlis (parliament) would cause all of our friends and adversaries to view the United States "with contempt."

To yield on the condition requiring the unblocking of assets (presumably including arms, spare parts and other military hardware) would be to "get involved in a war on the side of the combatant." Even to have considered the payment of "ransom," in the first place, only incites future acts of terrorism.

Now, you can't begrudge the Reagan camp some effort to discount in advance the impact of the hostages' possible return before Election Day. But we are going to have to be on dealing with Iran after the hostages' release, which means understanding (if not necessarily liking) them. It means trying to understand the forces at work throughout the ordeal of the hostages. It means remembering where Iran, by geography alone, fits inescapably into American security interests in the Persian Gulf.

And all this, in turn, calls for a little post-election tidying up of some of the worst of the preelection political rhetoric.

Nobody would argue that the Carter administration's handling of the crisis was uniformly competent. But the U.S. and allied sanctions and other pressures obviously did not cause a hardening of Iranian terms. The hostages were not put on trial. An important early Iranian demand for a public American apology for past wrongs against Iran was dropped.

In fact, a persuasive case can be made for the effectiveness of the international economic squeeze on Iran and the companion campaign mounted by the United States for almost total political condemnation by the world community. Some authorities insist this was instrumental in forging out of revolutionary chaos the ultimate Iranian consensus for a negotiated settlement of the hostage issue.

This does not necessarily add up to an encouragement to future hostage-taking.

As for the viewing-with-alarm of a possible under-the-table arms deal to buy the hostages release (and the consequent danger of violating U.S. neutrality in the Iraq-Iran war), only the president's most bitter detractors could think him reckless enough to try to cut a secret deal with what passes for a government in Tehran.

There is military equipment among the blocked assets, and unblocking those assets could free up arms deliveries to Iran. But Reagan himself gave unqualified support to acceptance of that condition when Ayatollah Khomeini offered it in September. True, that was before the war with Iraq broke out, but that only confirms the argument that economic pressure and isolation from the world community were the prime movers behind the ayatollah's initiative two months ago.

In any case, the administration has a point, as put by Secretary of State Muskie: the blocking of assets and other sanctions were tightly tied to the seizing of the hostages -- without foreknowledge of an Iraqi-Iranian war. Thus, he argues, to remove the retaliation in exchange for the removal of the grievance that gave rise to it is not to "tilt" toward Iran.

The point here is almost emphatically not that the Iranians should be excused for hostile and humiliating acts against the United States. The point is simply that a measured post-election approach to the hostage crisis offers the best chance of a solution consistent with the larger purpose of our Persian Gulf policy. One key to that is the territorial integrity of a relatively stable Iran, free of Soviet influence. An excessively hard line on the hostage issue is unlikely to contribute to Iranian stability.