BRUSSELS — ISLAMIC radicals who favor a hard line in dealing with the West are tightening their grip on Tehran's government. Signs now abound that pragmatic politicians who sought to normalize ties with the West are losing ground. Diplomats and observers of Iranian affairs point to two current examples: this month's resignation of a high-ranking foreign affairs official, and the direction of the campaign for August's presidential election.
Over the weekend, Iran announced the March 19 resignation of Mohammad Javad Larijani as deputy foreign minister. Mr. Larijani, who advocated a more moderate foreign policy, had taken the lead in relations with Europe and the United States.
Larijani's efforts, criticized by radicals, were severely set back when 12 European nations recalled their ambassadors for consultations to protest Ayatollah Ruhollah Khomeini's call for the killing of Britain's Salman Rushdie, author of ``The Satanic Verses.''
Most ambassadors are returning to Tehran, but ties with Britain were broken by an act of Iran's parliament.
But analysts say a development with more far-reaching repercussions than Larijani's resignation is the likely loss of influence for Iran's leading foreign-policy pragmatist, Speaker of Parliament Hashemi Rafsanjani.
Earlier this year, Mr. Rafsanjani had reportedly set his sights on Iran's presidency - on condition that the Constitution be revised ``and that the power of the presidency be reinforced at the expense of that of the legislative body,'' says a former parliament member, now in exile in Paris.
Now, although such a constitutional change is unlikely, Rafsanjani's nomination is being pushed by an unlikely source - radical Hojatolislam Mehdi Karrubi, a Rafsanjani deputy, parliament member, and by all accounts, rising political star.
The real aim of Mr. Karrubi and the radicals, the Iranian exile charges, is ``to kick his boss [Rafsanjani] upstairs, and gain full control over the parliament.'' Government officials and diplomats in Tehran as well as Iranian exiles agree that Rafsanjani will probably win the presidential contest. But that victory will be a hollow one, since the post of president is far less powerful than that of parliament speaker.
``When president, Rafsanjani will have to cope with a prime minister responsible to the assembly and not to him,'' says a journalist in Tehran. ``Every Cabinet member will have to secure a confidence vote by the parliament. Rafsanjani must understand that in our system, the president of the republic is not the most powerful man in the country.''
Between his election as speaker in July 1980 and his appointment by Ayatollah Khomeini as acting commander in chief of the armed forces in June 1988, Rafsanjani spent his time maneuvering between various assembly factions. Later he threw his weight behind politicians who wanted to end the war with Iraq and break Iran's political isolation. This policy was set back Feb. 14 when Khomeini called for Mr. Rushdie's murder.
``I will never let this country fall into the hands of the liberals,'' Khomeini said later. ``I reject those ignorant clerics who believe we should change our slogans under the pretext that they isolated us from the rest of the world. The Western world hates Islam. I will never accept that we compromise on our revolutionary principles in order to reestablish relations with Western or Eastern countries.''
According to the Iranian exile, ``Right after the Rushdie affair, the Combattant Clergymen Society, a group of radical clerics opposed to Mr. Rafsanjani, announced their support of his [presidential] candidacy. But Karrubi, the society's secretary-general, also said he opposed any revision of the Constitution that would reinforce the executive branch of the Islamic regime.''
Western diplomats in Tehran estimate the Combattant Clergymen Society has more than 50-percent support in parliament.
An Iranian student in London adds, ``Rafsanjani understands the trick. His cousin and staunchest ally, Hossein Hashemian, has begun claiming that Rafsanjani's departure to the presidency would be a great loss for the legislative body.''
Asked why, under these conditions, they expect Rafsanjani to leave his job as speaker, Western observers say he is in a corner.
``If he remains on top of the [parliament] he will have to seek reelection every 12 months,'' a European diplomat says. ``That means he'll be under constant pressure from the Combattant Clergymen Society. When elected to the presidency, he will be left in peace for five years.''
Karrubi, the man who hopes to succeed Rafsanjani, is in charge of the annual pilgrimage to Mecca, Saudi Arabia. He was in Mecca in July 1987, when 400 Iranian pilgrims were killed by police during riots. Western diplomats in Riyadh and Tehran say they have regularly noted a violent streak in Karrubi's anti-Western rhetoric.