If nothing else, Thursday's guilty verdict in the Jose Padilla case proves that the United States need not resort to star-chamber courts and primitive political justice to fight the war on terror. This kind of low-level aspiring terrorist can be handled easily by the U.S. constitutional system.

Soon the Bush administration will face a potentially embarrassing appeal that will challenge Padilla's military incarceration: The verdicts did not address the allegation by then-attorney general John Ashcroft, who accused Padilla of planning a radiological attack on the United States, for which he was held without charges in almost complete isolation for 43 months.

The Padilla case followed a typical post-Sept. 11 pattern. As terrorism expert Bruce Hoffman explained to one reporter: "For so many of these cases, there seems to be much less substance to them than we first assume or have first been told. There's an inherent deterrent effect in cracking down on any illicit activity. But the challenge is not exaggerating what they were up to — not portraying them as superterrorists when they're really the low end of the food chain."

Rather than face an embarrassing Supreme Court review of his incarceration in 2005, the Bush administration hastily charged Padilla and co-conspirators Adham Amin Hassoun and Kifah Wael Jayyousi in a federal court. The trio was charged with conspiring to murder, kidnap and support terrorism overseas and two counts of providing material support to terrorists.

Although the prosecution presented 22 witnesses and dozens of FBI wiretap recordings during the 3 1/2-month trial, there was no mention of the "dirty bombs" that Ashcroft raised. Prosecutors contended that "tourism," "football," "zucchini" and "eggplant" were code words for jihad, weapons and ammunition. The most compelling piece of hard evidence was a five-page al-Qaida recruitment form with Padilla's fingerprints found on it by CIA agents in Afghanistan in 2001.

In the end, Padilla was little more than an aspiring terrorist charged not for his crimes, but his intentions. Although a spokesman for the National Security Council at the White House thanked the jury for "upholding a core American principle of impartial justice for all," his celebration was premature. Although Padilla and two co-defendants were found guilty on all three counts — conspiracy to murder, kidnap and maim people overseas, and two terrorism material support counts — and will be sentenced by Judge Marcia Cooke on Dec. 5, the case is far from over.

One of Padilla's lawyers, Andrew Patel, told me, "The verdicts prove that there was no basis for Padilla's military detention." The prisoner's treatment in captivity will soon become a central issue.

According to his lawyers, Padilla was held in a windowless 9-foot-by-7-foot cell with no mattress, pillow, clock, calendar or contact with the outside world. His period of total isolation lasted almost two years while, according to his lawyers, interrogators plied him with hallucinogenic drugs in an effort to extract information.

Jose Padilla's family and Dr. Angela Hegarty, one of the forensic psychiatrists who examined him to determine his fitness to stand trial, believe that he now suffers from permanent psychological damage. Hegarty was struck by the prisoner's "absolute state of terror, terror alternating with numbness, largely. It was as though the interrogators were in the room with us." When pressed about his treatment in captivity, Padilla told Hegarty that he would not reveal "classified information" and even defended "the commander in chief" — signs of Stockholm Syndrome, in which the captive identifies with his captor.

The guilty verdict should serve as a sobering proof to people like Attorney General Alberto Gonzales, who argued that after Sept. 11 America needed a new legal paradigm to fight terror. According to Patel, "The constitutional plans laid out by the founding fathers worked during previous times of crisis like the Civil War and World War II and work today."

U.S. District Judge John Coughenour in Seattle sentenced Algerian Ahmed Ressam in July 2005 for plotting to bomb Los Angeles International Airport, and made an important point that was bolstered by the verdict in the Padilla case: "We did not need to use a secret military tribunal, detain the defendant indefinitely as an enemy combatant or deny the defendant the right to counsel."

To Coughenour, the most important message to the world is that American courts "have not abandoned our commitment to the ideals that set our nation apart." If we render our Constitution obsolete out of fear, the judge wrote, "The terrorists will have won."

Peter Maguire teaches history at Bard College in New York. He wrote this commentary for Newsday.