If witnesses of a crime describe the suspect as a blonde, blue-eyed, six-foot tall norwegian woman it would be silly to bring in four-foot tall black men to stand in a line-up for I.D.
To the extent that known terrorists have a profile law enforcement officials have to be on the lookout for that profile. It would be irresponsible if not inept not to do so.
However, if terrorists know that law enforcement and security personell are searching for a specific profile a bottle of Miss Clairol and some baby blue contact lenses can turn Mullah into a Ken doll in a matter of minutes. It would be foolish of terrorist not to disguise themselves.
It is also foolish not to profile Timothy McVeigh types, or the American Taliban John Walker Lindh.
In short -- profiles work. In short -- profiles don't work. The only effective security is total vigilance and random, thorough checks at entry points.