The letter was signed M. Ali, Elmwood Court, Rockville, and its tone was half pleading, half angry. "Islam does not allow harming safeers," that is, members of the diplomatic corps . . . Islam does not allow to kill someone unless he has been proved a murderer . . . Islam very strictly prohibits damaging someone else's property . . .

"I would request the media to stop calling what is happening in some parts of the world as 'Islamic violence,' as what is happening has nothing to do with Islam."

On Connecticut Avenue in the District, Arnold Speiser was also sitting down to write a letter to the editor.

"Recent events in Iran, Pakistan, Saudi Arabia and elsewhere in the Moslem would cause me to think that Islam is giving religion a bad name," he commented.

Tehran, Islamabad, Karachi, Izmir, Dacca, Tripoli -- to the American mind it has seemed a spreading revolution of religious extremism uniting Moslems of various nationalities in a common hatred of heathen America.

In this age of Shorthand headlines and instant television analysis, Americans have tended to explain the irrational news for abroad as a "resurgence of Islam."

Television images have reinforced these perceptions: armed gunmen chanting Moslem slogans, women in dark robes, self-flagellating fanaties and, everywhere, the frowning face of Ayatollah Ruhollah Khomeini

As the crisis in Iran drags on, however, Middle Eastern experts are speaking out against what they view as distortions here. Americans, they say, have wrongly blamed Islam for what is essentially a string of political upheavals.

"We are equating Islam with chanting mobs," said Michael Hudson, director of Georgetown University's Center for Contemporary Arab Studies. "There is a temptation to portray Moslems as naturally fanatic.

"Newpapers show sinister pictures of Khomeini blended in with the word Islam. We are identifying Khomeini with a whole culture when his views are deplored by most of the Moslem world."

Hudson describes a visit two weeks ago to Kerbela in Iraq, a holy city for Shite Muslims, Khomeini's minority sect. "It was during the holy days of mourning so black flags were flapping from the mosques, with their golden domes and minarets. People were praying on the street.

"But no one brothered us. I was talking with a government official about Khomeini who had lived there in exile. The man remarked -- not the official position of his government, of course: 'We made one mistake. We should have poisoned him.'"

In Beirut, Hudson said, Palestinians were complaining, "This guy Khomeini is bad news for us. He's giving Islam a bad name."

Islam is the world's second largest religion with some 800 million followers. Christianity has 985 million. Founded by the prophet Muhammad in the seventh century, Islam incorporates many of the teachings of Christianity and Judaism.

Islam's "five pillars" of religious faith are the belief in one God, daily prayers, taxes on the rich to care for the poor, fasting and pilgrimage to holy shrines -- all concepts familiar to Christians.

Scholars here bemoan the fact that Islam is hardly understood in America, although Moslems are a majority or a substantial minority in 70 countries. The spread of Islam across Africia and Asia is such that Arabs now form a minority of the faith. The largest Moslem population are in Indonesia, India, Pakistan, Bangladesh and the Soviet Union.

"It is a form of American hysteria to play up [these events] as Islam against the U.S.'" said Samih Farsoun, an American University professor who heads the Association of Arab-American University Graduates. p

"Everyone in Iran is a Moslem, so it is curious to call these Islamic mobs. It like calling a mob in France a Christian mob . . . It is true that Khomeini's movement calls itself Islamic, but in a dominated society, whatever, identity it has is asserted in a fight against foreigners."

Lucius Battle, former ambassador to Egypt, deplores "stereotyped newspaper cartoons" of Arabs and the general ignorance of the Moslem world.

"The majority of Americans believe Iranians are Arabs," he said. "They're not Arabs at all. There are enormous variations among Moslem countries. Saudi Arabia is far different from Egypt. There's a tendency here to see all of them as one."

Battle sees recent events in Iran and other Moslem countries not as Islamic phenomena, but as "a reaction against too rapid change in culture. People were not able to absorb the changes so quickly."

To improve America's images of Islam. Battle and a group of other Americans with Middle East ties organized a committee to commemorate the 15th century of Islam. However, the program of a lectures, films and exhibits, which was to begin this month, was posponed after the Iranian crisis began.

The negative image of Islam comes against a background of anti-Arab feeling which some scholars suggest amounts to racism. In a paper presented to a Georgetown University seminar in April, Michael Suleiman of Kansas State University, surveyed 40 years of American public opinion polls.

"While in the 1930s and 40s, existent anti-Semitism was directed against Jews, it is today mostly directed against the Arabs," he said.

A startling poll of American attitudes by Patrick Caddell in 1975 found than Jews to be thought of as "backward," "underdeveloped," "greedy" amd "barbaric." Jews were at least four times likelier than Arabs to be described as "honest," "friendly" and "like Americans."

Columbia University professor Edward Said, in a recent book, "Orientalism," argues that because Christian Europe was for centuries threatened by Arabs. Turks and the spread of Islam, westerners have tried to affirm a "superior" identity. For the West, to understand Islam has meant trying to convert its variety into a monolithic undeveloping essence . . . its people into fearsome caricatures," he writes.

"'Islam' cannot explain everything in Africa and Asia, just as 'Christianity' cannot explain Chile or South Africa."

As for the "barbaric" system of justice -- severing hands for theft, stoning for adultery -- practiced in a few Islamic countries, Said asks: "Was Islamic punishment, which tantalized the press, more irreducibly vicious than, say, napalming Asian peasants?"

David Long, a State Department Islamic expert, says Khomeini no more represents Islam than the cult of Rev. Jim Jones or the violence in Northern Ireland typifies Christianity. "A lot of things are done in the name of religion," he said, adding that Americans should look at their history of burning witches at the stake and banning alcohol before making fun of Moslems.

He dismisses references to Islamic fundamentalism as "a narrow characterization. There's a worldwide disillusionment with the blandishments of the 20th century," he said.

"It's happening in the U.S., too. Episcopalians and Roman Catholics are becoming charismatic Christians. You have fundamentalists in Israel and India. Everybody is searching for roots at a time when all the old verities are under assault."

A February article in the Columbia Journalism Review was sharply critical of press coverage of the Iranian revolution. "Region is one of the major cultural barriers for American reporters covering Iran (and for their editors back home)," it contended.

"Would it occur to American reporters covering the Vatican consistently to refer to priests in their everyday garb as 'black-robed?' This descriptive pharase regularly is applied to mullahs. For that matter, would it occur to a North American reporter to atics?"

The misperceptions of Americans are not due to malice, so much as cultural arrogance, scholars suggest. It is possible to be considered an educated person here and yet know virtually nothing about Islam, one of the great civilizations of the world.

More than half of high school world history teachers had never taken a course on the Middle East, yet thought themselves qualified to teach the subject, a recent survey found. Although Indonesia is the largest Moslem country with 140 million inhabitants, only 127 Americans were studying the Indonesian language, a 1977 survey of universities here revealed.

Yet if we are often ignorant, so are they. Americans found it almost laughable that Khomieini assumed American blacks might support him against the U.S. government because of racism here. "[Many Moslems] have a bad opinion of us and we of them," said Georgetown's Hudson. "It may be a cliche but there is a cultural communications gap."