IRAN'S FOREIGN MINISTER sent Americans what may have been a complicated message yesterday. The main part was menacing, arrogant, defensive and intolerable; the other -- if there actually was another part -- seemed to carry a just perceptible between-the-lines hint of a possible solution to the five-week-old crisis. Given the fragmentation and incipient anarchy of the Tehran scene, it is difficult to know not just if there are two policy lines but which is the more important. Correctly, however, the United States seems to respond to either one. This keeps the responsibility for the crisis precisely on the side that precipitated it: Iran.

In his menacing aspect, Sadegh Chotbzadeh threatened to summon an "international grand jury" to investigate American policy in Iran since the United States put the shah back in the throne in 1953. The way he explained it, this body would be a kangaroo court fit to put Bertrand Russell to shame. Its effect would be more than endangering to the hostages brought before it. If the regime insists on pursuing that course, the United States will have no choice but to intensify the pressures it has been applying, hitherto with restraint, for the last five weeks.

But Mr. Ghotbzadeh also had some other things to say. He asked Americans to "realize our grievances" and to demonstrate "more understanding" for the way Iranians feel about the American impact on their lives over the last 25 years. Until the hostages are released, Americans are not going to look sympathetically on anything about Iran. And few Americans, we judge, would at this moment offer the one-sided, full-throated, self-flagellating condemnation of their country that Mr. Ghotbzadeh no doubt has in mind. But there is a fairness in Americans that would let them countenance a reasonably objective review of the period if the element of duress and humiliation were removed by the freeing of the hostages.

Have Iranians forgotten so soon that, when the shah finally did leave Iran, the United States quickly opened up a whole range of cooperative projects with the new regime? Notwithstanding Mr. Ghotbzadeh's neurotic suggestion yesterday that the admission of the shah into the United States was intended as a prelude to a second American restoration of him, there is no inclination in the administration and in most sectors of public opinion to roll back the clock 25 years. But there is also virtually no willingness to stand by while Iran tramples on international norms and mistreats and threatens the hostages. The only conceivable basis for ever resuming the trend toward good relations with the post-shah order that was developing remarkably well before the assault on the embassy is for the Iranians to let the hostages -- all of them -- go.