GOV. REAGAN said the right thing about the hostages. Responding to Ayatollah Khomeini's latest set of demands, themselves seemingly pared down from an earlier and longer list, the Republican presidential candidate said the United States should simply agree to most of them. It should cancel American claims against Iran, release Iran's frozen assets and promise not to intervene in its internal affairs. The only Khomeini demand Mr. Reagan set aside was one for return of the former shah's property; that, he explained, is not in the U.S. government's hands. He recommeded agreeing to do all this, moreover, right off: not to engage in a long negotiation about it but just to agree to the three Khomeini demands and then to insist that the 52 American hostages be returned at once. Be done with it.

It is possible that Mr. Reagan will now be charged at home with barging in and yielding too much too soon. The answer, it seems to us, is that he is not negotiating in the first instance with Tehran; Jimmy Carter is. Gov. Reagan is in the first instance addressing Jimmy Carter. He is freeing the administration of the anxieties it has felt that Mr. Reagan would hover on the right, threatening to undercut any Carter effort to negotiate the hostages' return. Mr. Reagan would now seem to have left the president plenty of room over the next few months to continue his policy of cautiously but energetically exploring Iran's terms.

This is not to say the Reagan initiative has no political dimension. It will probably strike many Americans as an example of fair-minded, no-nonsense, presidential decisiveness -- a quality that Mr. Carter has had full opportunity to show in the White House. But the Reagan response does more than that. A large part of Mr. Carter's reelection strategy has been to suggest that, on foreign policy in particular, Gov. Reagan is an unlettered, ineducable primitive, capable for political cause of savaging necessarily sensitive diplomatic affairs. On the Iran issue at least, that particular campaign strategy now may be frustrated.

As to whether the Reagan approach would work if it were to become official policy, only a test could tell. There is a real question whether the new Khomeini demands represent either his final formulation or that of the Iranian parliament or of the particular terrorists holding the Americans. A case can be made, however, that there is a point beyond which it is self-defeating to wait until everything shakes down on the Iranian side. That could take forever. The Americans have already been captive nearly a year. It is at least conceivable that a clear, clean American position, forthrightly stated, could make its own contribution to untying the political knots that bind the hostages still.