The FBI's singling out Arab Americans for antiterrorism questioning is defended by Charles M. Lichenstein and Paul M. Joyal {op-ed, Jan. 21} as necessary and appropriate. I strongly disagree. No American should be singled out for FBI questioning or investigation because of his or her ethnicity, religion or political views.

The authors are wrong when they suggest that pre-Gulf crisis FBI antiterrorist efforts were hampered by constraints that need to be loosened in this time of crisis. On the contrary, the FBI has had extraordinary success in its counterterrorism programs.

A decade ago there were more than 100 incidents of terrorism per year in this country. Using sophisticated techniques, but focusing on criminal activity, the FBI has steadily reduced the threat to a very few incidents per year -- four in 1989 and an equally small number last year. Since 1983, there has not been a single foreign-controlled terrorist attack carried out in this country.

The criminal standard adopted by Republican U.S. Attorney General Edward Levi in 1976 should be the guidepost for the FBI today: Leave Americans alone unless there is a suspicion of criminal activity or unless a legitimate lead is being followed. Fishing expeditions and investigations of Americans because of their national origins should have no place in the arsenal of the FBI.

DON EDWARDS U.S. Representative (D-Calif.) Chairman, Subcommittee on Civil And Constitutional Rights Washington