THE GULF crisis has raised the threat of terrorism -- instigated by Saddam Hussein and directed against American targets both abroad and in this country. Hence, the increased security at federal buildings and airports, and the decision of the Immigration and Naturalization Service to photograph and fingerprint visitors holding Iraqi and Kuwaiti passports. These have been telling signs of a nation assuming a wartime footing. Given the pronouncements out of Baghdad, these countermeasures are inconvenient but necessary security precautions against possible terrorist attacks.

Yet it is exactly at times such as these that government must take care not to circumscribe the rights and freedoms of its citizens. Regrettably, that may have happened last week during the course of a special Federal Bureau of Investigation program focused on Arab Americans.

FBI agents contacted more than 200 Arab-American business and community leaders across the country, ostensibly to inform them of the bureau's intention to protect them against any backlash from the Persian Gulf crisis. Investigating and prosecuting hate crimes and ethnically motivated violence spawned by Middle East turbulence is a legitimate job of federal law enforcement officials, so that aspect of the bureau's initiative was welcomed by Arab Americans. But FBI agents also used the occasion to gather intelligence about possible terrorist threats. This is where the FBI quickly wore out its welcome.

Organizations representing Arab Americans contend that agents asked citizens about their political beliefs, their attitudes toward the Persian Gulf crisis, Saddam Hussein and their knowledge or suspicions about possible terrorism. Deputy Attorney General William P. Barr denies any FBI intention to intimidate Arab Americans, as some community leaders fear. "At the same time," he says, "in the light of the terrorist threats . . . it is only prudent to solicit information about potential terrorist activity and to request the future assistance of these individuals."

But why does the government presume that Americans of Arab descent should know about "potential terrorist activity" or that this group of Americans is any more knowledgeable about such activity than any other? FBI spokesman Thomas F. Jones says it's because the bureau is aware of a number of terrorist organizations in the United States that "consist of people of Middle East descent" and that the "possibility exists that {terrorists} are living in Arab-American communities." In that way, he said, Arab Americans "could come into possession of information on potential terrorist acts."

It is a perilously flimsy rationale. It leaves the U.S. government wide open to the accusation that it is dividing Americans by ethnic background and singling out one group as a suspect class. If that were true, the government's conduct would clearly be constitutionally offensive and morally repugnant. To imply that Arab Americans -- some of whom are members of families that have been in this country since the turn of the century -- may have a special link to terrorists is both insidious and harmful. The government cannot go around making judgments and presumptions about citizens on the basis of their descent.

Like all Americans, Arab Americans have the right to be accepted and treated as individuals, and the government has a constitutional duty to observe and protect that right. Neither should the government invade the privacy or trample the dignity of one class of citizens. What is being seen now recalls the negative stereotyping that served as a basis for the shameful treatment of Americans of Japanese ancestry during World War II. Such stereotyping, with all its ugly and unfair implications, should not be allowed to take hold.