THE CONVICTION in Iran of reformist cleric Abdollah Nouri on charges of insulting Islam, after a highly public two-week trial that became a showcase for the defendant's stinging criticisms of the regime, is no surprise. But it is a dispiriting signal that Iran's hard-liners continue to hold the upper hand in an increasingly dicey power struggle. The special clerical court slapped Mr. Nouri with a five-year prison sentence and a five-year ban on political activity and closed his newspaper, Khordad.

The conservative clergy evidently remains determined to squelch press freedoms encouraged by President Mohammed Khatemi, who was quoted as telling pro-reform legislators after the verdict on his former deputy, "It seems we have been deprived of an experienced and competent colleague." The president expressed hope that "later stages of legal proceedings" would be kinder to Mr. Nouri. The judge in the clerical court, an institution that Mr. Nouri had denounced during his trial as entirely extra-constitutional, barred him from appealing the sentence.

Initial coverage of the verdict in reformist newspapers was harsh, and Khordad staff members promptly declared their intention of resuming publication under a different name, as other banned publications have done. Pressure for more openness and for a more flexible and modernized Islam seem unlikely to let up.

But indications also abound of the precarious nature of Mr. Khatemi's campaign. U.S. officials say that they see new evidence of Iranian support for terrorism abroad, and that they are "concerned by the discrepancy" between that evidence and official Iranian statements denouncing terrorism. International pressure has also failed to resolve the plight of 13 Iranian Jews imprisoned in Shiraz on cloudy charges of spying for Israel and the United States. Nor can the United States fail to be concerned by Iran's reach for nuclear and other weapons of mass destruction.

As Iran's internal struggle intensifies, governments eager for Mr. Khatemi's success and for his promised "dialogue of civilizations" cannot ignore the Iranian currents that run the other way.