In recent weeks, as the war against the Taliban regime and the al Qaeda organization has proceeded on the ground in Afghanistan, the Bush administration has moved aggressively to identify and question persons who may have assisted or shared the objectives of the Sept. 11 hijackers.

While the motivation for some of its domestic actions may be understandable, the administration appears to have been oblivious to, and disregarded, elementary rights that are constitutionally guaranteed to all citizens and that are widely assumed to apply to others such as resident aliens.

Since Sept. 11, more than 1,200 people have been detained for questioning. Of those, one senior law enforcement official estimates that no more than 10 to 15 are suspected of being al Qaeda supporters and are being held as material witnesses in the investigation.

Five hundred others are reportedly being held on various immigration charges. Seven hundred others are reportedly being held on a variety of state and local charges unrelated to Sept. 11. Despite congressional requests, the Justice Department has refused to provide any information regarding the identities of those jailed, where they are being detained, and the reasons for their detention.

The public has not been told whether any of those detained are citizens or resident aliens. For the last three weeks, the Justice Department has even refused to reveal how many are being detained.

On Oct. 26, the president signed into law the infelicitously titled and cutely abbreviated “Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act of 2001,” better known as the USA Patriot Act.

Among the act’s many provisions, perhaps the most controversial during congressional consideration was the granting of power to the attorney general to detain indefinitely any non-citizen about whom there are “reasonable grounds to believe” the individual may pose a threat to national security. The only limitation placed upon the attorney general is that the individual must be charged within seven days.

On Nov. 8, Attorney General John Ashcroft signed an order allowing federal prison officials to eavesdrop on conversations between attorneys of detained individuals and their clients if the latter are suspected of posing a threat to national security.

On Nov. 13, the Justice Department asked law enforcement officials across the country to question, on a “voluntary” basis, 5,000 men who had come to the United States from Middle Eastern countries in the past two years on temporary visas. At least a few municipal police chiefs — those of Ann Arbor, Mich.; Detroit; and Portland, Ore.; for example — refused to cooperate on the grounds that the effort would constitute ethnic and national profiling and would therefore violate state law.

The most problematic rollback of the rights we all take for granted occurred when President Bush, without any prior congressional consultation, issued a military order on Nov. 13. The order provides for the creation of military tribunals to prosecute non-citizens accused of terrorism. According to the guidelines of the president’s order, the decision as to whom to prosecute would reside with the president as commander-in-chief rather than a grand jury.

Any non-citizen, whether or not he or she was involved in some way with al Qaeda and the Sept. 11 hijackers, could be prosecuted by a tribunal. The trial would take place before a commission composed largely, if not exclusively, of military officers rather than a member of the judicial branch of government.

The trial would be held in secret instead of in open sessions. The defendant could be denied access to the evidence used by the prosecution. Attorneys for the defense would be selected by the military — that is, colleagues of the prosecutors and commission and subordinates of the commander-in-chief who initiated the prosecution.

The verdict would be rendered by the commission rather than by a jury. The standard for conviction would be the “probative value to a reasonable person” (whatever that means) rather than the conventional standard of “beyond reasonable doubt.” Conviction could occur by a two-thirds majority rather than by unanimity. Sentences could not be appealed to a federal or state court.

With the stroke of a pen, the president has swept away for all non-citizens the rights that, taken together, are widely regarded as the necessary guarantees for a fair trial.

Above and beyond that invidious effect, the president’s order is likely, paradoxically, to impede the prosecution of some who may have assisted the Sept. 11 attacks. It is unlikely, for example, that any member state of the European Union will extradite to the United States anyone arrested and charged with aiding or participating in the al Qaeda organization and the Sept. 11 attacks. Indeed, after a Spanish investigative judge charged eight individuals Nov. 18 with aiding in the preparation of the Sept. 11 attacks, prosecutors there made it clear to U.S. officials that extradition would in all likelihood be blocked.

Even if the United States were to agree that those individuals would not be subjected to the death penalty and would not be tried by a military tribunal, extradition will in all likelihood be blocked on the grounds that, with the creation of military tribunals, the United States can not be regarded as providing the same legal guarantees that Spain provides — a stipulation of its extradition law.

The prospect of secret trials by military tribunals is also likely to thwart efforts to extradite for prosecution those arrested since Sept. 11 in other European Union member states, including France, Belgium, the United Kingdom and Germany.

It is perplexing that the Bush administration, despite being strengthened in its war on terrorism with the additional powers granted by the USA Patriot Act, does not have enough confidence in the existing criminal justice system to rely upon it for the prosecution of those who may have been involved in some way with the Sept. 11 attacks.

It is also perplexing that the administration reportedly has decided to remove al Qaeda-related prosecutions from the office of the U.S. attorney for the Southern District of New York and relocate them in Washington, D.C. After all, that office has developed extensive investigative expertise over a number of years in regard to al Qaeda; it recently completed the successful prosecution of some of those responsible for the bombings of the American embassies in Nairobi and Dar es Salaam in August 1998.

Congress has an important role to play in monitoring the investigative and prosecutorial activities of the executive branch in the war against terrorism.

It should begin by examining the detention of all those who are not material witnesses in the investigation, the recent decision to allow eavesdropping on certain heretofore privileged attorney-client communications, the president’s decision to employ military tribunals for the prosecution of certain suspected terrorists or their accomplices, and the decision to remove al Qaeda prosecutions from the U.S. Attorney’s office in New York.

David R. Cameron is a professor of political science and director of the program in European Union studies.