To the mistrial in the case of Sami Al-Arian, the Florida professor in the dock on terrorism charges, we say “God Bless the United States of America and Attorney General Ashcroft.” The jury in Florida may have acquitted Mr. Al-Arian of half the charges and failed to agree on the other half, which precipitated the mistrial. But the trial exposed the professor as having been deeply enmeshed in the internal workings of Palestinian Islamic Jihad,a terrorist group that has killed well over a hundred people in Israel, Gaza, and the West Bank, mostly through its favored technique of suicide bombings. Two of his alleged confederates were acquitted, while another was also placed in limbo by a partial verdict. Mr. Al-Arian has been in prison for the past two-and-a-half years, and the right move is to keep him for a new trial on the serious charges on which the jury failed to agree.

One wonders where was President Clinton’s attorney general, Janet Reno. It was in the mid-1990s, when the pick-up-truck driving Floridian was attorney general, that the activities for which Mr. Al-Arian was eventually brought up on charges first were in the news. Federal agents raided the professor’s so-called think tank and home in 1995. Mr. Al-Arian notes that Ms. Reno failed to act on the evidence. Kind of like Mr. Clinton and Osama bin Laden. It wasn’t until after 9/11, when Mr. Ashcroft was at the helm of the Justice Department, that the authorities finally acted. General Reno’s failure to act when the evidence was fresh no doubt hampered the government’s ability to bring this case home.

More broadly, the case against Mr. Al-Arian illuminates nothing so much as the difficulties of fighting a war with the tools of the criminal justice system. Imagine if all the detainees in Guantanamo or other overseas locations were given a full criminal trial with the standard of “beyond a reasonable doubt.” Some might find juries as lenient as the one that failed to convict Mr. Al-Arian. The Supreme Court last year recognized in Hamdi v. Rumsfeld and Rasul et al. v. Bush that the detainees should have access to some type of process by which innocent or mistakenly detained individuals can seek their own release. But it has stopped short of giving all the detainees full access to the American criminal justice system. Often the evidence lies outside of jurisdictions where America can compel its production.

How the Justice Department will proceed now is something to watch. This is not like, say, Eliot Spitzer losing on the vast majority of his charges against a lowly financial trader and holding out for a retrial on a handful of counts. The charges against Mr. Al-Arian on which the jury failed to decide are major, including terror-related fraud and conspiracy charges. Americans deserve to have these charges decided by a jury one way or another. Even if acquitted, Mr. Al-Arian may be subject to removal from America under a standard of proof that is less than required in a criminal proceeding. Those who saw the charges against Mr. Al-Arian as primarily a violation of academic freedom are no doubt celebrating the partial acquittal issued yesterday. For our part, we have been covering this story since the 1990s and our heart is with the victims murdered by Mr. Al-Arian’s friends in the Palestinian Islamic Jihad.