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.

More than 1,180 men, most of them Middle Eastern, have been locked up in connection with the September 11 mass murders with virtually no public disclosure of who they are, where they are, or what crimes or immigration violations they have been suspected of committing. A regulation is quietly slipped into the Federal Register authorizing government officials to listen in on consultations between some of these detainees and their lawyers. A presidential order allows for future military detention and trials of foreigners accused of terrorist war crimes.

Few things concentrate the mind like the prospect of a nuclear mushroom cloud in your own neighborhood. So please concentrate on this: I asked Ambassador Thomas Graham Jr., a sober, respected, retired career arms control official who was President Clinton’s special representative for nonproliferation and disarmament from 1994-97, to quantify the risk of nuclear terrorism. Here is what he said, from Moscow, via cell phone:

Suppose the FBI receives an anonymous tip that an apartment in Trenton, N.J., was used by Middle Eastern terrorists to prepare the anthrax-laced letters that have convulsed the nation. Could it get a search warrant? Possibly not: Under current case law, an anonymous tip falls short of the "probable cause" necessary to justify searching an apartment.

The portion of Attorney General John Ashcroft’s proposed anti-terrorism bill that has attracted the most controversy since it was made public on September 19-the so-called "indefinite detention provision"-may turn out to be less far-reaching and less controversial than it first appeared. Therein lies a lesson about how best to reconcile Ashcroft’s urgent request for new powers with Congress’s need to deliberate carefully on this complex and multifaceted bill before passing laws that could be with us for decades.