One reason aggressive agents were restrained as they tried to go after Zacarias Moussaoui is that liberals like myself — and the news media caldron in which I toil and trouble — have regularly excoriated law enforcement authorities for taking shortcuts and engaging in racial profiling. As long as we're pointing fingers, we should peer into the mirror.

The F.B.I. took new steps yesterday to expand its powers — allowing it to snoop on mosques, libraries and the Internet, for example — and they make sense. We must also relax a taboo, racial profiling, for one of the lessons of the Moussaoui case is that it sometimes works.

Transportation Secretary Norman Mineta bars airport security screenings based on religion or ethnicity. That's why aging nuns are plucked out of airport lines for inspections of their denture bags, why women with underwire bras are sometimes subjected to humiliating inspections after the metal detector goes off. But let's be realistic: Young Arab men are more likely to ram planes into nuclear power plants than are little old ladies, and as such they should be more vigorously searched — though with no less courtesy. El Al, the Israeli airline, has the world's most effective air security system, and it's all about racial profiling.