IT LEAKED OUT the other day that the president's domestic affairs adviser and his speech writer, at a White House staff meeting, had expressed qualms about the possibility that the United States might end up using force in the Iran crisis. In the usual Washington fashion, this came out as an embarrassment to the president, an indication that his policy was so dubious it had failed even to win the unqualified blessing of certain of his closest aides.

Yet there is another possible reading, one that we find truer to the facts as known and more useful to the president's policy and credibility. What the leak came down to was that at least two of the president's advisers -- no doubt there are more -- had become persuaded that when he said he would consider using force if American and allied sanctions do not soon effect the release of the hostages, he meant it. The reported jitters, in other words, were not so much evidence that his policy is flawed as that it is being taken seriously and not least by people who may have reservations about it. To put this in perspective, imagine a story that reported that key White House aides had expressed reservations about whether the president really intended to mine or blockade Iranian ports. Dissension, if that is the term -- and we are not at all sure that it is -- is not the problem of this president. Credibility is.

Anyway, it is not necessarily an argument against his policy that the crisis, if unchecked by an access of common sense in Tehran, may induce Jimmy Carter to take military action, which may in turn produce some consequences painful to the United States. It is a statement of precisely the intent that the administration should be trying to convey. To say that the only consequence or the sure consequence would be the prompt and safe return of the hostages is not only foolish on its face; it also is completely at odds with the necessity to have others believe that the United States means to go through with its now-chosen policy, even if the costs are high. This is the meaning of credibility. Mr. Carter's prior record has made it an uphill and unavoidable task for him to earn respect for his threats now.

To be sure, the president is not, and should not be, conveying that he will pay any costs. His policy proceeds, however, on a judgment that Iran will find the costs of the crisis unacceptable sooner than the United States will. This seems to us a reasonable judgment. What Americans seek from Iran, after all, is not its defeat or humiliation but merely its delivery on a promise that its own president and foreign minister found eminently acceptable just a few weeks ago. The point of the pressure now being applied is not simply to inflict distress. It is to suggest to the Iranians that the price of keeping the hostages is going to get -- and quickly -- unacceptably high.