The Bush Justice Department’s focus on preventing terrorist acts rather than solving past crimes is justified by the magnitude of the threat. It’s unfortunate but understandable that by throwing a broad net to catch people who might possibly be terrorists, the government has arrested and detained hundreds of Middle Eastern men on the basis of unconfirmed suspicions that-in the vast majority of cases-have been or seem likely to be dispelled. What’s unfortunate and unforgivable is the mounting evidence that many of these men have been treated badly or abusively while detained, even after being cleared of involvement in terrorism. Such mistreatment will not win the hearts and minds of potential informers, and it will ultimately prove unhelpful to the war on terrorism.

Anglo-American jurisprudence has for centuries aimed at finding and prosecuting those responsible for completed crimes, and has largely shunned "preventive detention," or locking up unconvicted suspects who might be dangerous. "Imprisonment to protect society from predicted but unconsummated offenses," Justice Robert Jackson wrote in 1950 in Williamson v. United States "is … unprecedented in this country and … fraught with danger of excesses and injustice." But since September 11, Attorney General John D. Ashcroft has explicitly embraced a preventive-detention approach to counter-terrorism. His goal is to disrupt terrorist cells by locking up hundreds of men of Middle Eastern descent, based on unconfirmed scraps of information suggesting their possible links to terrorism.

In most cases, this scanty evidence falls far short of the "probable cause" traditionally required to charge a suspect with a crime and to lock him up if he can’t meet bail. So the Administration has invoked alleged immigration law violations and minor criminal charges as technical grounds for locking up people who could not be detained based on mere suspicions of terrorist links and would not be detained but for those suspicions. "Let the terrorists among us be warned," Ashcroft declared on October 25. "If you overstay your visas even by one day, we will arrest you. If you violate a local law, we will … work to make sure that you are put in jail and … kept in custody as long as possible."

In effect, Ashcroft has supplemented the traditional presumption that suspects are innocent until proven guilty with a new presumption that possible terrorists should be detained until proven harmless-until, in the words of INS spokesman Russ Bergeron, "it has been absolutely ascertained with as much certainty as humanly possible that the individual is not linked … to terrorism."

So far, so good. While many civil-libertarian critics see this detain-until-proven-harmless approach as a dangerous betrayal of the presumption of innocence, I see it as a dangerous but necessary expedient to deal with unprecedented threats. As Harvard Law Professor Laurence Tribe has written, "The old adage that it is better to free 100 guilty men than to imprison one innocent describes a calculus that our Constitution-which is no suicide pact-does not impose on government when the 100 who are freed belong to terrorist cells that slaughter innocent civilians, and may well have access to chemical, biological, or nuclear weapons."

The problem is that-far from treating detentions as a regrettable but necessary evil-officials from Ashcroft on down appear to be gratuitously treating the detainees like terrorists. Although little is publicly known about most of them, the media have carried horror stories told by more than a dozen people who plausibly claim that officials arrested them unceremoniously, interrogated them rudely and even abusively, limited their access to families and lawyers severely, threw them into jails where guards and other prisoners taunted and (in at least one case) badly beat them, kept them behind bars long after abandoning any claim that they were terrorists, and offered those released little explanation, no apologies, and no compensation.

Consider the case of Ali al-Maqtari, a teacher of French from Yemen who was jailed for almost eight weeks based on a groundless suspicion of terrorist links and immigration charges such as overstaying his visa while seeking resident status, for which he apparently qualified based on his June 1 marriage to his wife Tiffinay, a U.S. citizen. In Senate Judiciary Committee testimony on December 4, al-Maqtari described an ordeal that started on September 15, when he and his wife drove up to the gate of the Army base at Fort Campbell, Ky., so that she could report for duty as a new recruit. Federal agents descended upon them, separated them, and interrogated them-"wild and full of anger," al-Maqtari recalled-for more than 12 hours. The agents accused him falsely of abusing his wife and conspiring with terrorists from Russia, claimed to have evidence that turned out to be nonexistent, and threatened him with beatings. Three days later, the agents, after giving him and his wife polygraph tests, told al-Maqtari that they now believed him and that he would probably be released the next day, al-Maqtari testified. Instead, he was locked up for another seven weeks in two jails in Tennessee, housed with hardened criminals, taunted by a guard, and limited to one phone call a week. Meanwhile, his wife, concerned that the Army might send her overseas while her husband was still in jail and that people seemed to mistrust her, gave up her hoped-for Army career and took a voluntary discharge. (A senior Justice Department official declined to comment when asked whether al-Maqtari’s story was true.)

The government may be justified in subjecting people such as al-Maqtari to the burden of detention for a few days, pending investigation. But shouldn’t it limit the damage by treating them with courtesy and housing them in comfortable surroundings away from hardened criminals? Or at least apologize to them after determining that they are not terrorists? "No," Ashcroft told Newsweek in an interview. "The United States of America does not apologize to law violators." Not even, it appears, to those charged with no more than overstaying their visas by a day.

What we have here is a refusal to face the new preventive-detention policy’s logical corollary: Most of these detainees have done nothing wrong enough to justify treating them like criminals. It is bad enough (if all too common) to mistreat suspects who have been arrested on the traditional basis of "probable cause" to believe that they have committed serious crimes. It is outrageous to treat as criminals and terrorists people who have been locked up based on mere suspicions that, as officials have reason to know, will in most cases turn out to be mistaken.

The pretense of shunning all politically incorrect forms of profiling-even while Ashcroft seeks to interview all of the 5,000 men between the ages of 18 and 33 who entered this country after January 1, 2000 with passports from certain Middle Eastern and other Muslim countries-makes matters worse. The Justice Department’s claim that these men "were not selected in order to single out a particular ethnic or religious group" may be true in a literal sense: The profile appears to be based on national origin, not ethnicity or religion as such. (It does not appear to include native-born Arab-American Muslims, for example.) But most people do not distinguish between these three forms of profiling. And Ashcroft has avoided acknowledging the national-origin profiling at the heart of his enforcement policy. This obfuscation of the real (and legitimate, if politically awkward) reasons for locking up Middle Eastern "law violators" who would be neither detained nor suspected of terrorism were they European, or Mexican, or Chinese increases the temptation for Ashcroft’s subordinates to come up with something to pin on the detainees and to exaggerate the seriousness of their alleged violations.

And even the smallest of immigration or criminal charges, once filed and invoked to justify detention, tend to take on a life of their own. "A large number of those still in detention," reports The New York Times, "are simply fighting the garden-variety criminal and immigration charges that the government used to arrest them in the first place. The FBI has lost interest in them as possible terrorists, but local authorities and immigration officials feel obliged to continue their pursuit of the original charges, which often resulted from tips or traffic stops."

Old habits die hard. It would take a forceful and sustained push by the Attorney General to mitigate his new preventive-detention policy’s dangers by breaking rank-and-file prosecutors, agents, and jail guards of their habit of assuming that "if a person is innocent of a crime, then he is not a suspect," in the memorable phrase of former Attorney General Edwin Meese III. So far, Ashcroft doesn’t even seem to be trying.